Detailed, evidence-based help for common painful problems

Voltaren Gel & Friends, A Review and Guide

The science of the topical pain-killers, analgesics that come from a tube, which can be effective without dosing your entire system

SHOW SUMMARY updated  by Paul Ingraham

ARTICLE SUMMARY

Voltaren® Gel (topical diclofenac) is a particularly safe and useful medicine. It’s an anti-inflammatory cream, so it can be applied only where you need it, instead of soaking your entire system with a medication, avoiding or dramatically reducing common side effects like indigestion, as well as some serious safety concerns associated with oral diclofenac. In the US, this drug is FDA-approved to treat osteoarthritis in “joints amenable to topical treatment, such as the knees and those of the hands,” but it probably also works for some other painful problems, such as some repetitive strain injuries and back pain. The evidence shows that it “provides clinically meaningful analgesia.” So this product actually works and gets a pass from skeptics and critics — a rare thing in the world of pain treatments!

Other topical analgesics are a mixed bag. The salicylates are likely effective but have more safety concerns (salicylate poisoning isn’t rare). The spicy-hot creams (Tiger Balm etc) won’t work miracles but may have some surprisingly benefits. Arnica creams are largely useless, especially the homeopathic preparations.

Word count: 5,500
Reading time: 25 minutes
Published: 2009
Updates: 7 major, 2 minor Since comprehensive update logging began in 2016. Document history is detailed at the bottom of the page.
Footnotes: 34
Citations: ~22
Photograph of a tube of Voltaren emulgel.

Think of Voltaren® Gel as “ibuprofen in a gel.” It’s actually the drug diclofenac, but ibuprofen is a much more familiar drug name in North America, where the product is still relatively new. It’s a topical anti-inflammatory medication,NSAID“Non-steroidal anti-inflammatory drug,” usually pronounced “en-sed.” and FDA-approved to treat osteoarthritis in “joints amenable to topical treatment, such as the knees and those of the hands.”1 The evidence shows that it “provides clinically meaningful analgesia.”2

This is an appealing treatment idea that actually works reasonably well: what a pleasure to be able to say that!3

Other topical pain-killers like topical salicylates, Tiger balm, and arnica

Voltaren is the most famous topical pain-killer, but it’s hardly the only one. Topical salicylates (cousins to aspirin) have been around for ages, and may even work better than Voltaren for some people and purposes. Other popular pain-relief ointments have never shown little potential, like the “spicy” ointments like tiger balm or Arnica creams (Traumeel, T-Relief). More on all of these below.

Why is Voltaren mainly for joints, and only some joints?

When the FDA refers to joints that are “amenable to topical treatment,” what do they mean? Is an amenable joint friendly and easy-going? No, just accessible: a pain-killing gel is useful only for joints that are not covered by a thick layer of muscle (like the shoulder). The medication gets diluted as it penetrates deeper into tissue, and a meaningful amount can only get into joints if they are just under the surface of the skin. The shoulder, hip, and spinal joints are notably quite deep.

For more superficial joints, though, Voltaren® Gel delivers a good dose of medication, while sparing the gastrointestinal tract from the harshness of NSAIDs — which are known as “gut burners,” because many people just can’t stomach ibuprofen. A topical drug mostly eliminates the risks associated with digesting the stuff.4

More conditions Voltaren might be good for (unofficially)

There are probably some good uses for Voltaren® Gel above and beyond what it’s already been specifically approved for (“off-label” uses). Here are some of the common conditions that, in my opinion, are also likely to be good targets for this drug.5

But I am not a doctor, and safety first: please check with your doctor before you start spreading topical diclofenac on painful problems it isn’t made for! (Especially if you already take several other drugs, or have complex medical issues.)

Availability and related drugs: different forms and cheaper generic versions)

Topical diclofenac is now widely available without a prescription in most places around the world. It was first available over-the-counter in the United States in early 2020, after being a prescription drug since 2007. Most other countries made it available without a prescription long before the US did (the FDA has a laudable history of being cautious with drug approval).

Topical diclofenac is now sold with several other major brand names and forms in addition to Voltaren Gel: Flector, Pennsaid, Rexaphenac, and Solaraze. There are also diclofenac patches, creams, and sprays.

Topical diclofenac with a transdermal patch delivery system.

Topical diclofenac with a transdermal patch delivery system.

Oral dicofenac has been around decades, and has been widely used globally since the 90s, and it continues to be prescribed frequently despite major safety concerns in recent history. More on this below.

Generic topical diclofenac has arrived! The first generic (cheaper) equivalent of Voltaren® Gel entered the marketplace in 2016, produced by Amneal Pharmaceutical, and that should be for sale most places now. There’s a rack of tubes of Voltaren by the till at my neighbhourhood drugstore, and I suspect pretty much every drugstore everywhere by now.

Voltaren for back pain too? Maybe! Surprisingly

I’ve emphasized that Voltaren is mainly appropriate for shallow inflammation, but there is some evidence that Voltaren might be able to “reach deeper.” This is hardly the stuff of medical certainty yet, but researchers Huang et al found that Voltaren treated pain coming from deep inside the spine, right in the centre.8

Photograph of a man holding his painful back.

Surprisingly, Voltaren may even help some kinds of deep back pain.

They concluded that it could be a “convenient and safe clinical intervention” for a few types of back pain. An anti-inflammatory gel will likely fail with many kinds of back pain, but there’s also virtually no down-side to trying. See my low back pain tutorial for extremely detailed information about medications for back pain.

However, it probably does not work well for deeper tissues in most cases.

For instance, there’s evidence that it doesn’t work at all for the muscle soreness that follows unfamiliar exercise intensity,9 probably because it can’t be absorbed far enough into thick muscle tissue — but oral NSAIDs do have a modest effect on that kind of pain1011 (one of the only things that does).

Voltaren Gel is probably better than ice

Ice is nice. I have some extremely thorough icing advice on this website.12 But Voltaren® Gel strikes me as being, well, better — definitely more evidence based.13 Or at least more convenient.

Obviously icing for pain relief has some advantages. It’s free, other than the cost of running your freezer. It’s extremely safe. And “natural.”14 But Vitamin I (for “ibuprofen”) in a gel? C’mon! That’s just awesome! Medication delivered straight to the inflamed tissues, and only the inflamed tissues … it’s kind of futuristic.

There’s no reason not to use both, of course. But Voltaren® Gel has the potential to make ice obsolete as a treatment choice, except for situations where you don’t have any Voltaren® Gel handy.

On the other hand, no medication is completely risk-free.

What do the skeptics say?

Many readers assume that “skeptics” will always favour mainstream and pharmaceutical treatments like Voltaren, but nothing could be further from the truth. Indeed, some skeptics are leading the charge against bad pharmaceutical industry science and practices (and a great example is Ben Goldacre’s new book, Bad Pharma: How drug companies mislead doctors and harm patients).

Pharmacist Scott Gavura of Science-Based Pharmacy was certainly skeptical about topical NSAIDs like Voltaren when he first tackled the topic early in 2011.15 “When I recently noticed a topical NSAID appear for sale as an over-the-counter treatment for muscle aches and pains … I was confident it would make a good case study in bad science.”

He was surprised, however, and he changed his mind when he read the evidence. Having worked with Scott as an editor, I know he can’t be persuaded by anything less than robust evidence. On a few occasions, Scott has proven himself to be even harder to impress than I am (which is really saying something). He concludes:

Over the past two decades, evidence has emerged to demonstrate that topical versions of NSAIDs are well absorbed through the skin and reach therapeutic levels in synovial fluid, muscle, and fascia. …

For chronic conditions like osteoarthritis, the data are of fair quality and are persuasive. On balance, there’s good evidence to show that topical NSAIDs are clinically- and cost-effective for short term (< 4 weeks) use, especially when pain is localized.

Nothing’s perfect, however, and some concerns about Voltaren are covered below.

Where’s the fire? Treating “inflammation” may be a bad premise in many cases

Are you sure that you’re actually inflamed? Don’t answer too quickly.

One concern about the use of products like Voltaren is that several conditions may be less inflammatory in nature than they seem like. Patients usually assume that the “burning” pain of repetitive strain injuries like tendinitis is caused by inflammation. Seems reasonable.

But classic, acute inflammation is almost entirely absent, especially after initial flare-ups have died down (but pain is still carrying on).

While it is extremely likely that tendinitis is still inflamed in some sense,16 it’s somewhat doubtful that they are inflamed in a way that NSAIDs are actually good for. The biochemistry of cranky tendons is very “here be dragons” on the map of biology — large and unexplored. There’s probably some overlap between the biology of acute, classic inflammation and the subtler biology of chronic tendinitis, but no one really knows.

So the value of Voltaren for tendinitis is simply unclear. You can read about this in much greater detail in my RSI article: Repetitive Strain Injuries Tutorial: Five surprising and important facts about repetitive strain injuries like carpal tunnel syndrome, tendinitis, or iliotibial band syndrome

Don’t forget that exercise is also an anti-inflammatory medication

Note that moderate exercise is almost certainly anti-inflammatory as well.17 Which is cool.

Never just use Voltaren (or any pain-killer). Ideally, even the safest pain-killer should only be used sparingly, and to make it easier to exercise — whatever exercise you can do without excessive discomfort.18 Even if you’re really hurting, you may still be able to do easy pain-free range of motion exercises. Just beware of overdoing it while medicated!

How diclofenac works

Diclofenac suppresses inflammation, fever, and pain mainly by blocking production of prostaglandins, a signalling molecule involved in a huge array of biological processes — which is how all the NSAIDs work, broadly speaking.

What seems to be different about diclofenac is that it’s better at doing NSAID-ish things than other NSAIDs. For instance, it may inhibit prostaglandin-making in both of the two common ways, whereas all the other NSAIDs are either one or the other. But the biochemistry is dazzlingly complex, and there are several other possible mechanisms (and mysteries) for making it more potent (and dangerous).

The drug is active biologically for just an hour or two as traditionally measured, but when absorbed into the synovial fluid of joints, it sticks around for least ten hours, which may account for why it particularly makes a difference for arthritis pain.

3D ball-and-stick representation of a Diclofenac molecule

More about safety, and the trouble with oral diclofenac

Long term and/or large oral doses of any of the NSAIDs can be extremely dangerous, even lethal. They “nuke” your entire system with much more active ingredient than you really need, all of it absorbed through the digestive tract and distributed through your entire circulatory system.

These drugs can and do cause complications at any dose, and are linked to heart attacks and strokes and ulcerations of the GI tract. What a bunch of jerks!

But oral diclofenac is a special kind of awful.

Diclofenac is an extremely popular drug and it is also associated with serious cardiovascular risks. McGettigan et al:19

There is increasing regulatory concern about diclofenac. … Diclofenac has no advantage in terms of gastrointestinal safety and it has a clear cardiovascular disadvantage.

This has been in the news quite a bit, and NPR had a hit in 2013 with this headline: “World’s Most Popular Painkiller Raises Heart Attack Risk.” And it’s not wrong, that headline. It’s not hype and alarmism — there is a real problem.

Topical diclofenac is a completely different animal than oral

The difference between oral and topical is extremely important. Spreading a medication on your skin is not the same thing as swallowing it.

Because Voltaren Gel is applied to the skin, dramatically less medication reaches the bloodstream — only a tiny fraction of what you would get from oral usage.2021 It is safe to assume that cardiovascular risks of moderate topical use are negligible compared to oral diclofenac, because so much less medication is actually getting into general circulation, and that is what the evidence now shows.22 Multiple studies have concluded that topical NSAIDs are both effective and safe.232425

At correct dosages for limited time periods, I think Voltaren Gel is probably almost completely safe: the worst side effect is probably the chance of irritated skin. ScienceBasedMedicine.org agrees:26

The main advantage of topical NSAIDs is the reduced exposure of the rest of the body to the product, which reduces the side effect profile. Given the toxicity of NSAIDs is related in part to the dose, it follows that topical treatments should have a better toxicity profile. Consequently, the cardiovascular risks of topical diclofenac, even in those with a high baseline risk of disease, should be negligible with the topical forms.

Some skin side effects for some people

I am definitely not saying Voltaren is completely safe or risk free. No drug is. The drug is still being absorbed, but instead of being a “gut burner” it can be a “skin burner.” From the Voltaren® Gel website …

The most common adverse reactions reported in Voltaren Gel clinical trials were application site reactions in 7% of treated patients. With all NSAIDs there may be an increased risk of serious cardiovascular thrombotic events, myocardial infarction, and stroke, which can be fatal.

Sounds bad, doesn’t it? But those warnings are primarily there in an abundance of legal and medical caution provoked by the problems with oral NSAIDs. For short-term, moderate topical use, I believe the benefits clearly outweigh the minor risks.

What about long-term use?

This drug was basically invented as an arthritis treatment. Those patients may be interested in using topical diclofenac regularly and indefinitely. Is that kind of long term usage safe? Is regular use of any medication a good idea?

There is no good data on long term safety that I’m aware of. It probably doesn’t exist yet.

In principle, long-term use of any medication should be minimized as much as possible. The benefits of topical diclofenac aren’t so great that they justify the risks of frequent use indefinitely.

If I wished I could use it that way, I’d probably plan to take usage breaks: just stop using it for a while, a few times a year.

On the other hand, it’s probably about as safe for regular use as any medication gets. But that’s just an educated guess, extrapolating from the short term safety data.

What about other common pain problems? Could it help low back pain, neck pain, and muscle pain?

A lot of people who read this are going to want to try it on their low back pain, neck pain, and/or other kinds of muscle pain. Will it work? The only honest answer is, “Who knows?” I have no clinical experience with this yet, and certainly it’s unstudied. It might be worth trying, in moderation, with the full awareness that there’s every possibility that it could be a waste of time and money.

Here’s why it probably won’t work …

Low back pain and neck pain often involve a substantial amount of muscle pain,27 and muscle pain is not particularly inflammatory by nature. Muscle knots (trigger points) are more like “poisoned” muscle than injured muscle. Although there’s some anecdotal evidence that taking an anti-inflammatory medication reduces muscle pain, mostly it doesn’t seem to work very well. One of the classic signs of low back pain powered by muscle, for instance, is that ibuprofen doesn’t have much effect on it.

A topical NSAID gel isn’t likely to either.

Also, many painful factors in neck, back and muscle pain are deep inside the body — probably much deeper than Voltaren® Gel can “reach.” For instance, if your low back pain is coming from the facet joints — small joints deep in the spine, under a thick layer of muscle — chances are that a topical treatment simply doesn’t stand a chance of having an effect.

That said, why not try it? It’s almost certainly safer than popping ibuprofen! Although not tested and approved for reckless experimentation on any pain problem, obviously the entire point of Voltaren® Gel is to limit exposure to the active ingredient. So you might choose to experiment — taking full responsibility for your actions, of course, and not suing me if something goes horribly wrong, because of course I’m not actually recommending it. 😉 Seriously: just run it by your doctor.

Other topical pain-killers: from literal snake oil to the perfectly cromulent salicylates

This article is focused on Voltaren because it dominates drugstore shelves these days, and it’s what 90% of people search for. But it’s hardly the only or first pain-killing ointment. Oh no! Pain-killing unguents might literally be older than stone tools — while there’s no direct evidence of any such thing, it’s extremely likely that early humans discovered that the juices of some plants had medicinal effects when rubbed on the skin. So there is a long, colourful history of pain-relief ointments, including literal snake oil:

The grease of a snake mixed with verdegreece, healeth any part of the eye that is broken: but the slough or old skin which they cast off in the spring, doth clarifie the eie-sight, if the eies bee gently rubbed therewith.

Pliny the Elder, The historie of the vvorld (trans. by Philemon Holland), 1634

There are three other prominent modern examples of pain ointments:

  1. arnica creams, either plain or homeopathic (diluted)
  2. rubefacients, the “spicy” ointments like Tiger Balm
  3. the salicylates, which are often combined with rubefacients

Arnica creams

Arnica creams are widely available both in traditional herbal formulations and much sketchier homeopathic ones that contain only trace amounts. Standard homeopathy involves extreme dilution of ingredients, to the point of literally removing them.28 While homeopathic arnica creams tend to be the least diluted of homeopathic nostrums, but are still highly diluted by definition. They do not work, period — credible evidence of benefit is just as scarce as the arnica molecules.

Unfortunately, it’s unlikely that even full-strength arnica is medically potent, let alone when diluted down to traces. It’s no willow tree (the original herbal source of acetylsalicylic acid, AKA Aspirin), and it’s not like aspirin works any miracles either. For much more information, see Does Arnica Gel Work for Pain?.

Rubefacients (Tiger Balm et cetera)

Photo of a jar of Tiger Balm.

These products feel hot and cause superficial capillaries to open up wide. They contain a chemical irritant or rubefacient, which literally give you a mild chemical burn, because they are literally spicy: capsaicin is the active ingredient, and it comes from chilis.

The burn is a counter-irritant — a neurological “distraction” from your pain (see diffuse noxious inhibitory control). Counter-irritation is a real thing, but it’s not a powerful thing.

And yet, surprisingly, capsaicin has actually gotten some high fives from science.29 Some of the effects of capsaicin are more exotic than expected — like actually making nerve endings shrivel and retreat.30 Interesting stuff, and probably worth a try (cheap and quite safe). Just keep your expectations low: these products may be mildly useful, but they are unlikely to compete with Voltaren for most people. For more information, see the rubefacients section of my heating article, “Is tiger balm hot?

Salicylates, cousins to aspirin

The large chemical family of salicylates has several maybe-medicinal members. Aspirin (acetylsalicylic acid) is the star of the show, but minty methyl salicylate (MeSa) has been widely used in ointments for decades, as well as many other products (mouthwashes, soaps of all kinds, bath salts, suntan lotions, and so on). Just look for some kind of “salicylate” on the label.

Certainly these are interesting chemicals. Plants use MeSa in complex ways for signalling and self-defense — it can attract the natural enemies of plant predators. And it might be an analgesic in humans, but the science isn’t exactly settled, despite their long history of usage Harvard Health Publishing in 2019: “There’s little, if any, rigorous research into methyl salicylate’s effectiveness as a pain reliever,” which seems a touch dismissive to say without any substantiation, so I checked myself… and, sure enough, good job Harvard. There truly isn’t much data! A 2004 review found little to review,31 and the situation wasn’t much better in 2014,32 and the latter review concludes that “evidence does not support the use of topical rubefacients containing salicylates for acute injuries or chronic conditions.”

On the other side of the question, there certainly is some positive evidence,33 and Anderson et al declared in 2017 that “its analgesic action is beyond question.”34 That’s a bit much, but their paper was more focused on the safety concerns about MeSa:

Over-application of the topical preparation containing the drug, or its accidental ingestion, invariably results in salicylate poisoning and in severe cases can be fatal. The drug has been a regular feature of the US National Poison Database Survey over the past decade and continues to pose a risk to children and adults alike.

Ruh roh! Clearly ordinary, moderate usage is safe, and in broad strokes these concerns are right in line with other major pain-killers. But you don’t see major concerns about overdose poisonings and experts arguing about efficacy with Voltaren… which might be why it’s winning in the marketplace!

Still, anyone with a persistent pain problem should probably test, in moderation, all of the above. Except homeopathic arnica—that’s just nonsense.

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About Paul Ingraham

Headshot of Paul Ingraham, short hair, neat beard, suit jacket.

I am a science writer in Vancouver, Canada. I was a Registered Massage Therapist for a decade and the assistant editor of ScienceBasedMedicine.org for several years. I’ve had many injuries as a runner and ultimate player, and I’ve been a chronic pain patient myself since 2015. Full bio. See you on Facebook or Twitter.

What’s new in this article?

Nine updates have been logged for this article since publication (2009). All PainScience.com updates are logged to show a long term commitment to quality, accuracy, and currency. more When’s the last time you read a blog post and found a list of many changes made to that page since publication? Like good footnotes, this sets PainScience.com apart from other health websites and blogs. Although footnotes are more useful, the update logs are important. They are “fine print,” but more meaningful than most of the comments that most Internet pages waste pixels on.

I log any change to articles that might be of interest to a keen reader. Complete update logging of all noteworthy improvements to all articles started in 2016. Prior to that, I only logged major updates for the most popular and controversial articles.

See the What’s New? page for updates to all recent site updates.

Feb 23, 2021 — Major additions, more than a thousand words on “other topical pain-killers: from literal snake oil to the perfectly cromulent salicylates.”

2020 — Edited for readability. Added some images.

2020 — Widespread minor improvements, collectively substantial. Most notably added information on mechanism of action, some more safety information, more about brands and availability.

2019 — Added small new section: “Remember, exercise is also an anti-inflammatory medication.”

2018 — Added a brief anecdote about a personal success.

2018 — Added a small section about the safety of long-term regular use.

2018 — Science update. Added several citations substantiating what was previously presented only as a rational opinion: topical NSAIDs are a lot safer than oral NSAIDs.

2016 — Added link to new opioids article, and a footnote clarifying the mechanism of action of “gut burning.” Added information about availability and the new generic equivalent of Voltaren.

2015 — Significant safety update (and a reassuring one).

2009 — Publication.

Notes

  1. FDA approval does not remotely mean that something is “proven,” and in fact FDA approval only requires evidence of efficacy for drugs (not proof). For everything else they regulate, they are focused on safety. For instance, FDA approval of food additives and medical devices mainly just means “probably safe” (for medical devices, they officially require “valid scientific evidence that there is a reasonable assurance that the devices are safe and effective for their intended uses”).

    And of course they screw up; there’s a long history of embarrassing examples of things the FDA should never have approved. So FDA approval is hardly a guarantee of anything, but it is also better than nothing.

  2. Altman R, Barkin RL. Topical therapy for osteoarthritis: clinical and pharmacologic perspectives. Postgrad Med J. 2009 Mar;121(2):139–47. PubMed #19332972 ❐

    ABSTRACT


    Nonsteroidal anti-inflammatory drugs (NSAIDs) have shown efficacy in patients with osteoarthritis (OA) pain but are also associated with a dose-dependent risk of gastrointestinal, cardiovascular, hematologic, hepatic, and renal adverse events (AEs). Topical NSAIDs were developed to provide analgesia similar to their oral counterparts with less systemic exposure and fewer serious AEs. Topical NSAIDs have long been available in Europe for the management of OA, and guidelines of the European League Against Rheumatism and the Osteoarthritis Research Society International specify that topical NSAIDs are preferred over oral NSAIDs for patients with knee or hand OA of mild-to-moderate severity, few affected joints, and/or a history of sensitivity to oral NSAIDs.

    In contrast, the guidelines of the American Pain Society and American College of Rheumatology have in the past recommended topical methyl salicylate and topical capsaicin, but not topical NSAIDs. This reflects the fact that the American guidelines were written several years before the first topical NSAID was approved for use in the United States. Neither salicylates nor capsaicin have shown significant efficacy in the treatment of OA.

    In October 2007, diclofenac sodium 1% gel (Voltaren Gel) became the first topical NSAID for OA therapy approved in the United States following a long history of use internationally. Topical diclofenac sodium 1% gel delivers effective diclofenac concentrations in the affected joint with limited systemic exposure. Clinical trial data suggest that diclofenac sodium 1% gel provides clinically meaningful analgesia in OA patients with a low incidence of systemic AEs.

    This review discusses the pharmacology, clinical efficacy, and safety profiles of diclofenac sodium 1% gel, salicylates, and capsaicin for the management of hand and knee OA.

  3. The great majority of therapies and interventions that sound good actually don’t work all that well. In medicine, “common sense” rarely correlates with reality. I get tired of being the bearer of disappointing news about popular therapies and treatments, and it’s a genuine pleasure to have good news for once.
  4. The effect of NSAIDs on the GI tract is actually indirect: it’s not because the medicine comes into direct contact with the walls of the GI tract, but because the medication, once it is in the bloodstream, affects the behaviour of cells in the lining of the gut. So it’s actually just a matter of dosage. If you were to smear a diclofenac gel all over your body, you would absorb enough of it that it would be a “gut burner” too!
  5. I am basing my opinions on the well-established efficacy and safety of the drug for arthritis, and on a good working knowledge of the biochemistry of the drug, and extremely strong knowledge of the science of pain and injury.
  6. “Tendinitis” versus “tendonitis”: Both spellings are acceptable these days, but the first is the more legitimate, while the second is just an old misspelling that has become acceptable only through popular use, which is a thing that happens in English. The word is based on the Latin “tendo” which has a genitive singular form of tendinis, and a combining form that is therefore tendin. (Source: Stedmans Electronic Medical Dictionary.)

    “Tendinitis” vs “tendinopathy: Both are acceptable labels for ticked off tendons. Tendinopathy (and tendinosis) are often used to avoid the implication of inflammation that is baked into the term tendinitis, because the condition involves no signs of gross, acute inflammation. However, recent research has shown that inflammation is actually there, it’s just not obvious. So tendinitis remains a fair label, and much more familiar to patients to boot.

  7. To the extent that neck pain and headache may be caused by fact joint inflammation, Voltaren may be useful. It’s extremely difficult for anyone — patients or professionals — to confidently determine the specific cause of this kind of pain. However, treating conservatively and presumptively with topical diclofenac is one way to help figure out what’s going on. If neck pain eases with Voltaren use, it doesn’t exactly prove that the facet joints are involved, but it’s certainly a useful data point. This topic is discussed in more detail in both my neck pain and headaches tutorials.
  8. Huang ZJ, Hsu E, Li HC, et al. Topical application of compound Ibuprofen suppresses pain by inhibiting sensory neuron hyperexcitability and neuroinflammation in a rat model of intervertebral foramen inflammation. J Pain. 2011 Jan;12(1):141–52. PubMed #20797917 ❐
  9. Hyldahl RD, Keadle J, Rouzier PA, Pearl D, Clarkson PM. Effects of ibuprofen topical gel on muscle soreness. Med Sci Sports Exerc. 2010 Mar;42(3):614–21. PubMed #19952809 ❐
  10. Hasson SM, Daniels JC, Divine JG. Effect of iboprufen use on muscle soreness, damage and performance: a preliminary investigation. Med Sci Sports Exerc. 1993;1:9–17. PubMed #8423760 ❐

    An old and small but well-designed test of ibuprofen for muscle soreness, showing a modest but definite benefit for pain, but probably not function. In other words, ibuprofen reduced the soreness only, but had no significant effect on other outcomes, like muscle function and inflammatory markers.

  11. Tokmakidis SP, Kokkinidis EA, Smilios I, Douda H. The effects of ibuprofen on delayed muscle soreness and muscular performance after eccentric exercise. J Strength Cond Res. 2003 Feb;17(1):53–9. PubMed #12580656 ❐

    Another very small test of ibuprofen, very similar to Hasson 1993 in design and results: “ibuprofen can decrease muscle soreness induced after eccentric exercise but cannot assist in restoring muscle function.”

  12. For more detail, see another article on PainScience.com, Icing for Injuries, Tendinitis, and Inflammation: Become a cryotherapy master.
  13. There are a lot of reasonable reasons to try icing, but it’s not proven medicine. In fact, strangely, it’s almost completely untested. See Collins.
  14. Especially if you use organic, free range ice. From icebergs.
  15. ScienceBasedMedicine.org [Internet]. Gavura S. Topical NSAIDs; 2011 Mar 3 [cited 13 Mar 27].
  16. Dakin SG, Newton J, Martinez FO, et al. Chronic inflammation is a feature of Achilles tendinopathy and rupture. Br J Sports Med. 2017 Nov. PubMed #29118051 ❐

    This paper now stands as the best available evidence so far that rumours of inflammation’s demise in tendinopathy are exaggerated/oversimplified. There are no other important sources I’m aware of so far (as of early 2020), and Dakin et al. cite only their own evidence on this.

  17. Fu S, Thompson CL, Ali A, et al. Mechanical loading inhibits cartilage inflammatory signalling via an HDAC6 and IFT-dependent mechanism regulating primary cilia elongation. Osteoarthritis Cartilage. 2019 Jul;27(7):1064–1074. PubMed #30922983 ❐ PainSci #52660 ❐

    This is a highly technical petri-dish study of the effect of “exercise” (mechanical loading) on the inflammation signalling of cartilage cells. Basically, they mechanically stressed samples of excised cartilage and cartilage cells. The surprising, good-news result was that the researchers reported that moderate loading actually reduced inflammation. That is, fewer inflammatory signals were produced by the cells.

    While it is a near certainty that too much loading would increase inflammatory signalling, it is nifty that mechanical loading in the “just right” Goldilocks zone might actually be anti-inflammatory. It implies a very specific and substantive way in which “exercise is medicine.”

  18. A “window of opportunity” (WOO) in therapy is a period of minor pain relief or boosted confidence that facilitates normal activity/exercise, which in turn is what delivers the true rehab value. This is exemplified in some cases of frozen shoulder. A placebo can also generate a bit of WOO, but a good WOO is a little more substantive. The idea of WOOs is also often used as a self-serving justification for ineffective methods that only produce trivial, transient benefits. See “Windows of Opportunity” in Rehab: The importance of WOO in recovery from injury and chronic pain (using frozen shoulder as an major example).
  19. McGettigan P, Henry D. Use of non-steroidal anti-inflammatory drugs that elevate cardiovascular risk: an examination of sales and essential medicines lists in low-, middle-, and high-income countries. PLoS Med. 2013 Feb;10(2):e1001388. PubMed #23424288 ❐ PainSci #54748 ❐
  20. Holt RJ, Taiwo T, Kent JD. Bioequivalence of diclofenac sodium 2% and 1.5% topical solutions relative to oral diclofenac sodium in healthy volunteers. Postgrad Med. 2015 Aug;127(6):581–90. PubMed #26077436 ❐ “Systemic exposure to diclofenac is substantially lower after topical application as compared to oral administration.”
  21. PharmacyTimes.com [Internet]. Fudin J. Should Topical NSAIDs Have Strict Heart Risk Warnings?; 2018 March 10 [cited 18 Jun 12]. Although this article’s title implies concerns about topical NSAID safety, it ends up answering that concern with very reassuring data, and it turns into a piece suggesting that the FDA needs to make it clearer that only oral NSAIDs are of concern, while topical is an extremely safe alternative! “ … all topical vehicles of diclofenac delivery result in only a small fraction of the diclofenac that actually reaches the systemic circulation compared with the oral route.”
  22. Pontes C, Marsal JR, Elorza JM, et al. Analgesic Use and Risk for Acute Coronary Events in Patients With Osteoarthritis: A Population-based, Nested Case-control Study. Clin Ther. 2018 Feb;40(2):270–283. PubMed #29398161 ❐ “No significant associations were observed” between topical NSAIDs and acute coronary events.”

    Interesting side note: this study not only confirmed that oral NSAIDs increase the risk of heart attack, but that opioids do too! Despite the opioid crisis, this is not a widely recognized concern about that type of drug.

  23. Rannou F, Pelletier JP, Martel-Pelletier J. Efficacy and safety of topical NSAIDs in the management of osteoarthritis: Evidence from real-life setting trials and surveys. Semin Arthritis Rheum. 2016 Feb;45(4 Suppl):S18–21. PubMed #26806189 ❐ “Topical NSAIDs have a moderate effect on pain relief, with efficacy similar to that of oral NSAIDs, with the advantage of a better risk:benefit ratio. In real-life studies, topical and oral NSAIDs demonstrate an equivalent effect on knee pain over 1 year of treatment, with fewer adverse events due to lower systemic absorption of topical NSAIDs compared with oral NSAIDs.”
  24. Deng ZH, Zeng C, Yang Y, et al. Topical diclofenac therapy for osteoarthritis: a meta-analysis of randomized controlled trials. Clin Rheumatol. 2016 May;35(5):1253–61. PubMed #26242469 ❐ “Topical diclofenac is effective in pain relief as a treatment of OA. It may also have a potential effect in function improvement, which needs further studies to be explored. Although, some adverse effects were observed in the application of topical diclofenac, none of them was serious.”
  25. Zeng C, Wei J, Persson MS, et al. Relative efficacy and safety of topical non-steroidal anti-inflammatory drugs for osteoarthritis: a systematic review and network meta-analysis of randomised controlled trials and observational studies. Br J Sports Med. 2018 Feb. PubMed #29436380 ❐ “Topical NSAIDs were effective and safe for OA. Diclofenac patches may be the most effective topical NSAID for pain relief. No serious gastrointestinal and renal AEs were observed in trials or the general population.”
  26. Science Based Pharmacy [Internet]. Gavura S. How risky are NSAIDS?; 2015 Jul 25 [cited 16 Aug 18].
  27. This is one of the most important and useful major ideas presented and explained on this website. For full details and all the evidence, see the neck pain or low back pain tutorials.
  28. Homeopathy as a profession is rotten with dangerously irresponsible ideas, as shown in the BBC’s 2006 exposé of homeopaths in London recommending completely ineffective remedies to travellers in place of genuine anti-malarial medication (see News.BBC.co.uk [Internet]. Jones M. Malaria advice ‘risks lives’: Some high street homeopaths claim they can prevent malaria, a Newsnight investigation has found; 2006 [cited 12 Feb 19].) and numerous examples in 2020 of homeopaths claiming that they can prevent or treat COVID-19. Wikipedia has quite a good complete review of homeopathy. See Ingraham. Homeopathy Schmomeopathy: Homeopathy is not a natural or herbal remedy: it’s a magical idea with no possible basis in reality.  ❐ PainScience.com. 1601 words.
  29. Derry S, Sven-Rice A, Cole P, Tan T, Moore RA. Topical capsaicin (high concentration) for chronic neuropathic pain in adults. Cochrane Database Syst Rev. 2013;2:CD007393. PubMed #23450576 ❐
  30. Kennedy WR, Vanhove GF, Lu SP, et al. A Randomized, Controlled, Open-Label Study of the Long-Term Effects of NGX-4010, a High-Concentration Capsaicin Patch, on Epidermal Nerve Fiber Density and Sensory Function in Healthy Volunteers. J Pain. 2010 Jun;11(6):579–587. PubMed #20400377 ❐
  31. Mason L, Moore RA, Edwards JE, et al. Systematic review of efficacy of topical rubefacients containing salicylates for the treatment of acute and chronic pain. BMJ. 2004 Apr;328(7446):995. PubMed #15033879 ❐ PainSci #51927 ❐
  32. Derry S, Matthews PR, Wiffen PJ, Moore RA. Salicylate-containing rubefacients for acute and chronic musculoskeletal pain in adults. Cochrane Database Syst Rev. 2014 Nov;(11):CD007403. PubMed #25425092 ❐ PainSci #51924 ❐
  33. Higashi Y, Kiuchi T, Furuta K. Efficacy and safety profile of a topical methyl salicylate and menthol patch in adult patients with mild to moderate muscle strain: a randomized, double-blind, parallel-group, placebo-controlled, multicenter study. Clin Ther. 2010 Jan;32(1):34–43. PubMed #20171409 ❐
  34. Anderson A, McConville A, Fanthorpe L, Davis J. Salicylate Poisoning Potential of Topical Pain Relief Agents: From Age Old Remedies to Engineered Smart Patches. Medicines (Basel). 2017 Jun;4(3). PubMed #28930263 ❐ PainSci #51921 ❐