OMG SCIENCE

Capsaicin, the stuff in peppers, the stuff in the pepper spray. Also available now in topical preparations for use as a local analgesic, usually for injuries or arthritis.

Capsaicin binds to TRPV1, involved in sensing heat/pain on peripheral neurons, and lowers the threshold at which it activates. Typically it activates at temperatures that are dangerous. With a lowered threshold, body/room temperature suffice.

This is similar to menthol used in Ben-Gay, Icy Hot, etc which binds to TRPV8, and is sort of the polar opposite, minus the increase in pain transmission. Whereas your *caines like lidocaine block the Na ion channel and increase the threshold at which the neuron will fire, perhaps preventing it from firing entirely.


BROTELLIGENCE

Anyway, my personal experience here with a variety of tense muscles, injuries, soreness, etc is pretty interesting.

Lidocaine causes some minor numbing. Really nothing significant, even the Rx-only strength stuff I have.

Menthol is much more effective, as you probably are all quite familiar with. It numbs the effected area, but that's about it. Often I will feel more sore after using it, especially overnight, and have increased muscle tension in that area.

Capsaicin... is different.

The first time I applied it, I thought it wasn't doing anything at all. It seems to have an onset of effects closer to that of liodcaine than menthol. The exception to this is mucous membranes.

Overall, it seems to do very little to most areas of my body, regardless of how much I apply.

The exception to this is areas of muscle tension, pain, soreness, etc. Especially with a little warmer temperature, like placing your hand over the area once the capsaicin is applied, causes some fairly intense burning pain. My skin actually flushes in what it is effecting, and the burning sensation shoots along the path of the dysfunction. After it wears off, the area feels looser, less tense, like after a chiropractor-type "popping" motion or a really good tension-releasing stretch. (though not to the degree I've gotten from stretching)

The interesting thing is that I can apply it to an area broadly in which a single narrow muscle has chronic tension... with some time/heat, the pain shoots through the tense muscle but none of the surrounding area. I will also feel a release of tension sometimes in cases like the outside of my kneecap-- applying it there makes the burning sensation shoot down to my foot, which relaxes.

And even though the tense muscle's temperature was no different to my perception before the application, when I look at the area, only the skin above the effected muscle(s) is red and flushed with blood-- none of the skin above the surrounding area is, despite it being the same temperature and having the same amount of capsaicin applied.

Anyway, the final verdict isn't quite in on it yet, but if you don't mind a little heat and pain, check it out.

PS-- you cannot wash capsaicin off with water, it is not water soluble. Specialized pepper spray decon products work best, but milk caesins actually contain a TRPV1 antagonist that can disassociate the capsaicin from the receptor, so give milk a shot. (extra points this week only if said milk is from a hot bisexual chick at a swinger's club and your wife/husband is present. hey, I'm just being topical with the Lounge!)

Um, at any rate, do NOT rub the capsaicin in with your hands and then rub your eyes without scrubbing your hands well or wearing gloves while applying it... it is VERY potent in mucous membranes and the eyes.

Cap typically works best when used regularly because it depletes Substance P locally.

Yeah, forgot to mention that-- the main way it does analgesia is as Benson says, and there's also a central endorphin release from the heat/pain perception.

Do I mix it in petroleum jelly?

It comes as a cream. I don't even really think you can find just a powder.