Capsicum

What is Capsicum?

Capsicum is the pepper plant group. It gives us chilli peppers, cayenne, paprika and sweet bell peppers. The hot types are used as food, as a spice, and as a herbal remedy.

The heat comes from capsaicin and related compounds. In remedies, capsicum is most often rubbed on the skin for pain. It is also sold as capsules for digestion, circulation and weight.

Evidence verdict: capsaicin on the skin has fair human evidence for some kinds of nerve pain. Most other uses, and most capsule uses, rest on tradition and small studies. Long traditional use is not proof that something works, and it is not proof that it is safe.

How does Capsicum work?

Capsaicin acts on a nerve sensor called TRPV1, which picks up heat and pain.

When you first apply it, that sensor opens. This is why the skin stings, burns or reddens.

With repeated use the pain nerve endings become less active. Skin sample studies in people show the fine pain fibres pull back for a while. This is the best-supported reason for its effect on nerve pain.

Eaten chilli works differently. In small human studies it raises heat output a little and may dull appetite. The effects are small and short, and they have not added up to lasting weight loss.

In lab and animal work, capsaicinoids also act on blood vessels, stomach lining blood flow and some bacteria. Whether any of that matters in people is not established.

What forms does Capsicum come in?

Capsicum is sold in many forms. The strength differs hugely between them.

- Fresh or dried pods, used as food - Cayenne powder, a kitchen spice - Capsules and tablets of cayenne or capsicum extract - Oleoresin, a strong concentrated extract used in products - Creams, gels and plasters, usually 0.025% to 0.075% capsaicin - An 8% capsaicin patch, applied only in a clinic by trained staff - Tinctures and throat or nasal sprays

Pepper spray also comes from capsicum. It is a weapon, not a remedy.

Where it comes from:

Capsicum peppers were grown in the Americas thousands of years ago. Mesoamerican peoples used them as food and as medicine.

After 1492 the plants spread fast to Europe, Africa and Asia. They became part of cooking and of folk medicine almost everywhere they landed.

Folk healers applied pepper pastes and plasters to sore joints and muscles. The idea was counter-irritation: warm the skin to draw attention from deeper pain.

Cayenne was also taken by mouth in 19th-century Western herbal practice. Thomsonian herbalists treated it as a warming tonic for digestion and circulation. These were traditional claims, recorded before modern testing existed.

What does Capsicum help with?

• Nerve pain after shingles: This is the strongest use. The high-strength 8% patch, applied in a clinic, helped a minority of adults get useful pain relief in pooled trials. Relief is partial, not complete, and it does not help everyone. Burning and redness during treatment are common.
• Painful nerve damage from diabetes: Trials of the 8% patch show modest pain relief for some people with painful foot nerve damage. Results are less consistent than for shingles pain. Check your feet with your care team before using anything on numb skin.
• Osteoarthritis joint pain: Tradition used pepper plasters on stiff, aching joints. Small trials of low-strength cream report some pain relief over a few weeks. The studies are small and hard to blind, because the cream stings. Treat the benefit as possible, not proven.
• Muscle and low back pain: Capsicum plasters have a long history for back and muscle ache. A few trials suggest short-term pain relief. The evidence base is thin and mostly older. Nothing here suggests it fixes the cause of the pain.
• Indigestion: Folk use treated cayenne as a digestive stimulant. A few small studies of chilli powder in functional indigestion reported less pain after several weeks. The trials are small and have not been widely repeated. For some people chilli makes reflux and stomach pain worse.
• Blocked or runny nose not caused by allergy: Capsaicin nasal sprays have been tested for long-term nose symptoms with no allergy cause. Small trials show some benefit. These were specific medical products used under supervision. Putting cayenne or pepper products in your nose yourself is not the same thing and can injure you.
• Appetite and weight control: Chilli is widely marketed for burning fat. Short human studies show a small rise in heat output and a mild drop in appetite. These effects are small and fade. No good evidence shows meaningful weight loss from capsicum capsules.

Which foods are rich in Capsicum?

1. Chilli peppers, fresh or dried
2. Cayenne powder
3. Chilli flakes and hot sauces
4. Paprika (mild)
5. Jalapeno, habanero and bird's eye peppers
6. Chilli oil and pepper pastes

Practical Tips:

Capsicum is an everyday food. Normal cooking amounts are safe for most people.

Sweet bell peppers are the same plant group but carry almost no capsaicin, so they do not burn.

If chilli triggers reflux, stomach pain or bowel symptoms for you, eat less of it.

What are the side effects of Capsicum?

• Burning, stinging or redness where the cream is applied
• Itching or dry skin at the site
• Blisters or raw skin with strong products or heavy use
• Severe eye pain and watering if it touches the eyes
• Coughing, sneezing or wheeze if powder or spray is breathed in
• Heartburn and reflux
• Stomach pain, nausea or loose stools
• Sweating and flushing
• Runny nose
• A short rise in blood pressure during patch treatment

Good to know:

Skin burning is very common and is expected rather than rare. It usually fades with repeated use over days.

Most reactions are unpleasant but not dangerous. The serious problems are eye injury, breathing in the powder, and deep skin burns from heat or tight dressings over the cream.

Stomach effects from capsules are common in people who are not used to chilli.

How much Capsicum should you take?

• Recommended daily: This page gives label-type ranges only. It is not advice for you, and strengths vary a lot between products. Skin creams and gels are usually labelled 0.025% to 0.075% capsaicin, used a few times a day. Capsule labels for cayenne often list 400 mg to 500 mg per capsule. The 8% patch is a prescription product. It is applied by trained staff in a clinic and is never a home product. Food amounts of chilli in cooking are a normal part of many diets.
• Best time of day: Time of day does not matter much for the cream. People often apply it on a regular daily schedule, since steady use matters more than timing. Some people avoid applying it right before bed, because the burning can keep them awake. Wash your hands well after each use, or wear gloves.
• With or without food: Capsicum capsules are usually taken with food. Taking them on an empty stomach makes burning and heartburn more likely. If they upset your stomach even with food, stop taking them. Food guidance does not apply to creams, gels or patches.
• Time to effect: Burning on the skin starts within minutes. That is not the pain relief, just the first sting. Any pain benefit from low-strength cream usually takes one to two weeks of daily use. With the clinic-applied patch, relief may build over days and can last weeks. For many people it does nothing useful at all, and that is a normal outcome.
• How long to take it: Skin products are usually labelled for short courses of a few weeks. Pain relief from capsaicin cream often needs daily use for one to two weeks before it is judged. If pain has not improved after a few weeks, stop and ask a doctor. Do not keep using it on skin that stays raw or blistered. There is no good long-term safety data for high-dose capsicum capsules.