Capsaicin – is it the magic bullet for Trigeminal Neuralgia?

I have been feeling more than a little guilty about the fact that I haven’t taken the time to post this much earlier … I have been looking through the various blogs and information sites on Trigeminal neuralgia in the last couple of days (Feb 2010) – and nothing seems to have changed at all in the past 10 years! In fact, the dominant paradigm for treating TGN seems to be a total reliance on surgical intervention, which is exceedingly worrying - and probably totally unnecessary.

So I am posting my experiences with trigeminal neuralgia and my highly successful treatment of it, for the benefit of other sufferers.

A biographical note. I am a biologist, with a PHD in neuropharmacology (not that that knowledge kicked in, until rather late! – as you will read), and am now a field-based conservation biologist. I have thought long and hard about this issue – and have discussed it with a number of my neurobiologist colleagues as well. Frequently being in the position of both sufferer and trained observer really sheds new light on the processes involved.


My experience

In late 1998 I was cleaning my teeth in the morning, and was suddenly hit by a pain as if someone had hit my head with an axe. The pain was intense but brief and then started to repeat itself a various intervals during the day. I suspected that it might be trigeminal neuralgia – and visited my dentist – who really didn’t have a clue, and tooth x-rays didn’t show anything. Over the next month or so – the pain came and went and at times became more ’classical’ in style (specifically in the mouth – especially when trying to eat.). I went the rounds of oral-surgeons and neurologists, had the CAT scans, all of which showed nothing (surprise!). I was initially put on Tegretol – which actually worked – at about 400 mg/day – but a mishap with a collapsing step ladder – caused me to fall and bang my canine tooth on a stainless steel sink top – ouch! – and the neuralgia hopped onto that tooth and all hell broke out (that canine tooth actually had been root canalled – and was dead as, but the injury to its ligaments triggered the shift – from the premolar next door). Eventually my dentist decided that an apiciectomy (cutting the nerve supply and ligament to that canine tooth) was the way to proceed – and carried it out – the relief was instant – and I was pain free for about 9 months. Then the little niggling twinges started again. So (foolishly ..but that’s what happens) I decided to have the apiciectomy repeated – as evidently the nerve would have grown back by then – so it was done – but this time the dentist did it with a vengeance – removing about 1 cm of the tooth root (radical, you might call it) – ouch! – and then it got infected (as it was a bloody big hole in my gum) – and the misery was severe – so out came the (otherwise perfectly good, canine tooth).

From then on the neuralgia just intensified – and the usual surgical ‘bulldozer’ treatments were offered – ablation, lifting insert etc. Knowing the not-so-remote possibility of getting thalamic pain (which is totally incurable) should any of these process fail – I decided that that wasn’t the way to go (and I hate hospitals).

Here’s where I should have known better ages ago – but it is funny how when you are the victim – objectivity flies out the window. I am trained as a neuroscientist – working on brain neurotransmitters (even tho I am now a conservation biologist ) – but the penny finally dropped - the pain I was experiencing seemed to be classical unmyelinated axon pain, especially given the stimuli that set it off – light touch inside the mouth mostly.

Hang on – I remember that there is a class of compounds that attack unmyelinated axons – and cause them to die back.

So I asked a colleague – and he suggested the only one he could think of – was Capsaicin, the active oleo-resin ingredient of chilli peppers.

I should point out that at this juncture I’d had the condition for 4 years, and was taking over 1 gram of Tegretol a day (plus paracetamol) – a thoroughly toxic mix – and it wasn’t working (the novelty of feeling as if your mouth was full of broken glass and razor blades 50x a day was starting to pall) – and I was seriously considering what tree on the side of the road to hit at high speed. (and the side effect of that drug dose (abuse) level was a severe attack of Rosacea – which really can’t be cured).

Some reading up – and a suggestion was for Capsaicin ‘candies’ (basically toffee with a heavy loading of Capsaicin) – nah – I think I’ll pass on that idea – Capsaicin at the level you need is not something you want swishing around in your mouth (unless you are an aficionado of Thai prawn balichow – but then – you probably wouldn’t be suffering from Trigeminal neuralgia either!).

So I came up with another idea…

I initially used 1% Capsaicin topically - made by mixing a commercial 0.075% water based cream (Zostrix - used for herpes zoster treatment) with pure Capsaicin at about 1mg/ml of cream - smearing this on an applicator made of mouth-guard plastic ( made by taking a 1/2 mouth impression, and casting it) - I contact glued small swatches of soft synthetic felt on the mouth-guard where I wanted to restrict the application - and on these I spread the Capsaicin cream and popped it in. Not particularly painful after the first try - but it causes massive salivation.- even after continued use. The advantage of this approach is that the Capsaicin stays where you need it, and doesn’t swirl about the mouth. I find that on taking the applicator out, it is wise to drink a large glass of milk to wash down the remains, and neutralise the effects of the Capsaicin (bit like eating all your Vindaloo curries in one shot) .

This all but eliminated the mucosal pain component of the neuralgia - and allowed me to eat normally without generating a deluge of lancinating pain (razor blades). It seemed to need repeating every couple of weeks.

It did not however help with the deeper pain. – but that was sensitive to the Tegretol – but back to the lower dose rate.


Later considerations… 2007

After having been effectively ‘neuralgia free’ for about 4 years – as a result of Capsacin treatments – I need to summarise my observations.

1) Capsaicin effectively ‘de-afferents’ (disconnects) the trigeminal ganglion – from a wide variety of sensory nerves (pain, touch and possibly chemical (nociceptive)), that rely on unmyelinated (‘D’ ) fibres. It does so, by causing these unmyelinated sensory nerve terminals in the oral mucosa to ‘die back’ a few millimetres (and probably reduces their synaptic efficiency at the other end) and it takes 1-3 months for them to grow back and become active. For our purposes the exact mechanism of the nerve ‘die back’ is not really relevant, but it is only the unmyelinated fibers that are affected.

It seems a peculiarity of the trigeminal ganglion (which is in effect a spinal dorsal root ganglion – but serving the face) – that in the presence of continued D – fiber sensory stimulation (which you may not even be aware of – termed ‘sub-liminal’), it develops what is known as a ‘excitatory surround’ – where the axons of the sensory cells send out connections (excitatory collateral afferents) to neighbouring cells that belong to the same ‘union’ (that is non-myelinated sensory cells) – such that excitation of merely a few neurons causes almost all the cells of that population of non-myelinated fibres to fire. Thus a small touch in the mouth is interpreted by the brain as a major pain onslaught. (Now, it is entirely possible that this could be occurring in the thalamus or the equivalent of the spinal substantia gelatinosa in the brainstem –it really doesn’t matter for the purposes of understanding – although understanding it may have some bearing on the likelihood of suffering from thalamic pain after trigeminal ablation). It also probably explains the rationale for the surgical approach of putting a pad between the trigeminal nucleus and the blood vessels under it – as the generation of the ‘excitatory surround’ has sensitised the ganglion itself to the micro-pulsations of the blood vessels. Best get rid of the excitatory surround with Capsaicin –and you can avoid the need for surgery.

2) Capsaicin, by ‘disabling’ these afferents (sensory inputs) causes these new excitatory connections to fail, (the nervous system is a dynamic system – and neural connections continually change according to the activity - use it or lose it!). This results in the trigeminal nucleus returning to a more ‘normal’ state. However – while there may be a genetic pre-disposition – in my experience, the post-trigeminal-neuralgia trigeminal nucleus seems to develop a strategy of ‘searching’ for other inputs that could trigger an attack. If these inputs happen to be ‘deep’ – say, unmyelinated fibres in the deep tissue - then Capsaicin is of no use in combating that particular source of stimulation (although it reduces the overall level of stimulation) and you will have to resort, at least temporarily, to anti-epileptics such as carbamazine (Tegretol) - which reduces the excitability of the ‘excitatory surround’ and have somewhat the same effect as Capsaicin. If this situation does happen (and it has happened to me, because I have been slack in applying the Capsaicin in time – too much else going on in my life at the time) – about 6 mo at a minimal dose of Tegretol (100 mg per day) plus the Capsaicin – should allow you to stop the Tegretol altogether.

3) Repeat Capsaicin treatment HAS to be undertaken (takes only 1/2 hr per day over 5 days) when ‘micro-twinges’ are felt (or preferably before). If you leave it longer – then you risk the problems mentioned above. Regular – about 2 mo intervals, application of Capsaicin, ensures that there is never enough non-myelinated sensory ‘drive’ to get the neuralgia active. However – now (Feb 2010) I have been twinge free for 9 months (after getting a mild attack – because I (guess what?) neglected to apply the Capsaicin in time - after about a year) – and have just done my first of 3 applications (why 3? – read on). I have not used Capsaicin in that intervening period.

4) Is there any sensory deficit as a result of using Capsaicin?? - virtually none, which is a great surprise. After an intermittent history of applying Capsaicin for 8 years – all I can really report is a slight sensation (as if I had drunk slightly too-hot coffee) on the upper jaw where the Capsaicin was applied. I haven’t done a serious investigation of the deficit. It makes you wonder what the role of these ‘D’ fibres is in normal sensation.

5) It is ESSENTIAL that you exhaust the possibilities of using Capsaicin ‘de-afferentation’ (with or without Tegretol) before you allow yourself to be subjected to the various invasive surgical approaches suggested by the neurology cohort! – Chemical (and even small scale dental surgical) de-afferentation is reversible and repeatable, surgical intervention on the trigeminal nucleus is NOT, and such surgical intervention can leave you not only with a serious sensory deficit on one side of your face, but it can also result in varying degrees of facial paralysis – as well as permanent total local anaethesia of that part of the face! If it really goes wrong – then you could be faced with a permanent (thalamic) neuralgia (anaethesia dolorosa) that NOTHING can cure!

6) After trying USP pure Capsaicin (in combination with Zostrix), I was given a ‘personal pepper spray’ by a departing student from Germany (how she got it into Australia, I don’t know) – however – after it sitting on my desk for 3 years – I decided to investigate its contents – expecting that it would be a powder – probably crude Capsaicin oleoresin – but no – it was an red oily extract of chilli – and fairly ‘lethal’. So I tried it, instead of the USP variety – it was much stronger (so the initial application can be seriously eye-watering!!) – but you only seem to need 3 applications. Being an oily liquid it is easier to apply to the mouthguard.

Tegretol, while a very effective first line of attack, at high doses has a large spectrum of very nasty side effects – I was taking over 1 gram per day for almost 6 mo (plus Panadol) – and this has resulted in severe Rosacea – which is quite disfiguring, despite being off Tegretol for over 3 years now.

Another reason to use the Capsaicin treatment asap!


The major advantage of using the Capsaicin approach is that is totally NON-INVASIVE, is totally REVERSIBLE (and, if it concerns you – it is a natural product). It is not pleasant to use for the first and maybe the second occasion (but the reduction of the pain it produces is a good indication that it is working). But all indications are that it works – and I suspect that the mechanism is fairly similar to that I have described.

Reading some of the recent blogs – concerns have been raised about the long-term effects of Capsaicin – better ask the Thais and Mexicans! – in this application you are using it for a maximum of 2 hours spread over 3-5 days, every 6 months – I really don’t believe that it is an issue. You spit it out anyway!

Making the equipment - Do It Your Self!

The mouth-guard (aka ‘dental splint’) - was constructed from scraps of thermo-plastic flexible mouth-guard material suppled by a friendly dentist. I took an impression of my teeth on the upper jaw with alginate impression mix (ouch!) –made a casting-stone cast, and moulded the heated (boiling water) mouth-guard plastic over the stone cast (with several layers of handkerchief between me and the hot plastic) - and then trimmed it. The sharp edges can be easily softened and moulded with a gas cigarette lighter. I glued (with fabric contact adhesive) a layer of thin synthetic cloth where I needed to apply the Capsaicin. None of these processes are particularly complex – but you may need to turn to a friendly dentist or dental technician for help.

The images show components of the the process. It is fairly simple – the taking of the impression could be rather painful – but it only takes a few minutes for the alginate to set (it is water based) – If anyone is interested I could put together a kit of materials for a small cost ($50) plus postage.


Picture caption

The kit of materials I use. Left hand side top – the cast of my upper left jaw used to make the mouth-guard immediately below it. You can see the strip of fabric that the capsaicin (bottom little bottle) is applied onto. On the right – a piece of mouth-guard plastic (already used by the dental technician – wasteful eh? – the rest usually goes in the bin) - with the chunk I used cut out. Under it is the synthetic non-woven cloth used on the mouth-guard.

Using it


I load the cloth strip with just one or two drops of the pepper spray oil and smear it on both sides (wherever it is needed). Use your finger – but don’t rub your eyes afterwards! Pop it in your mouth - nothing much will happen for about 10 secs – and then the heat of the Capsaicin will start to be felt –and will become quite painful initially (though for some reason, I never found it to trigger an attack). You will drool and spit a lot. I go out in the garden and pull weeds furiously – spitting the while – good therapy!

You can’t use the treatment if you have mouth ulcers as well (and the presence of mouth ulceration is a pretty good indication that you have a real beauty of a tooth abscess that has to be removed. Do what a good friend of mine did – refused to leave the dentist’s office until they’d found the ulcer – as in her case – it didn’t show up in the x-rays. The dentist did eventually find it, pulled the tooth (and it stank) – and the neuralgia and the ulcers cleared up almost immediately).

Capsaicin extract.

"Pepper spray" refills are available in some countries – you’ll have to pull them to bits to get the canister and nozzle out. You need to be very careful in handling it – do it outside! If you can’t get pepper spray – get the hottest chillies you can obtain, chop them up finely – seeds and all and soak them in the smallest volume of cooking oil you can manage – maybe with a little gentle heat (in boiling water) – you should get a red oil, which should be adequately pungent for the job. Treat it in the same way as the pepper spray. (or you could extract cayenne pepper powder with oil).

5 ml of this material should just about last a lifetime!

Capsaicin caplets. Huh?? – these seem to be a new twist – unfortunately taking Capsaicin internally will have NO effect whatsoever – it exerts its effects DIRECTLY on the nerve fibres in the oral mucosa (and also it can work on the skin too – so direct application of the oil to the affected skin could produce the same effect).

Caplets seem to be a mechanism by which sufferers try to avoid having to deal with the sensitive areas directly. Having been there, done that (and got the T-shirt) – you just have to put up with the temporary inconvenience – Yes the anticipation of an attack can almost be as bad as the attack itself – but get over it – you are going to get the attack anyway – so you might as well use it to aid the cure – and apply the Capsaicin. If things are really rough – get some xylocaine gel and rub it around the affected side of your mouth – then apply the Capsaicin – (or or when you make the gum impression to make the mouth-guard) – it doesn’t affect the Capsaicin’s action.

Medical Study

I’d really like to get a cohort of trigeminal sufferers to record their experiences with using Capsaicin in this manner – as I suspect it could revolutionize its treatment, but it would have to be carried out in a consistent manner. Please contact me hugh@austrop.org.au.

Other observations – I wonder if what I have observed with my experiences with trigeminal neuralgia, could be applied to other forms of neuralgia involving spinal dorsal root ganglia. Unmyelinated sensory fibers are found every place in the body –especially the skin (think of itch, sunburn etc). – and reducing their ‘drive’ to affected dorsal root ganglion cells could alleviate some forms of neuralgia – Zostrix is used for the neuralgia of Herpes zoster (shingles) - but I suspect much stronger preparations would be required for skin penetration.

An interesting question – is the incidence of trigeminal neuralgia less in cultures with a high chilli useage (think Thai and Mexico)? Don’t confuse chilli with black pepper (Piper sp.) - which chillis displaced when they were introduced from S America.