Capsaicin is taken from chilli peppers. It works mainly by reducing Substance P, a pain transmitter in your nerves. Results from RCTs assessing its role in treating osteoarthritis suggest that it can be effective in reducing pain and tenderness in affected joints, and it has no major safety problems. Evidence for its effectiveness for fibromyalgia is related to a single trial.
What is it?
Family: Herbal medicine extracted from chilli peppers (Capsicum family)
Scientific name: Capsaicin
Other names: Axsain®, Zacin®, chilli, pepper gel, cayenne
Capsaicin is the main medicinally active component of chilli peppers which is taken from the plant’s tissues. It’s licensed in the UK for osteoarthritis and you can get it on prescription in the form of gels, creams and plasters.
How does it work?
Several studies have found that capsaicin can use up Substance P. Substance P plays an important role in transmitting pain signals from nerve endings to your brain. It’s also involved in activating inflammatory substances in joints.
Is it safe?
There are no major safety concerns in applying capsaicin gel/cream. You may feel a burning sensation when the gel touches your skin. This is because capsaicin also binds to specific receptors in nerve endings called VR1, producing a burning sensation which isn’t caused by any tissue damage. Brief skin redness is common, but high doses of capsaicin can cause skin blisters.
A review of capsaicin applied to the skin to treat chronic pain (not specifically related to osteoarthritis, rheumatoid arthritis or fibromyalgia) concluded that around one third of people experience a reaction around the area where the treatment is applied.
It’s important to keep capsaicin away from your eyes, mouth and open wounds because it will cause irritation. There have been no reported drug interactions.
Most trials have used either 0.025% or 0.075% of capsaicin gel applied to the skin four times a day.
Capsaicin trials for osteoarthritis
A summary of the scientific evidence on capsaicin for the treatment of osteoarthrit Read more
Capsaicin trials for fibromyalgia
A summary of the scientific evidence on capsaicin for the treatment of fibromyalgia. Read more
References for the evidence on capsaicin. Read more