What is Balsam of Peru?

Balsam of Peru is a thick, dark brown resin tapped from the trunk of the Myroxylon balsamum tree in Central America. It smells of vanilla and cinnamon. In Western herbal and pharmacy practice it has been used mainly on the skin, in salves for grazes, cracked skin, bedsores and haemorrhoids (swollen veins around the back passage).

It was also added to cough syrups and lozenges, and dentists once used it in wound dressings after tooth surgery. Despite the name, most of it comes from El Salvador. It reached Europe through Peruvian ports, which is how it got its name.

Today Balsam of Peru is better known as an allergen than as a remedy. It is one of the most frequent causes of allergic skin reactions found on patch testing (a skin test that checks what your skin reacts to), and cosmetic rules in Europe restrict the crude resin.

The honest verdict: it has a long, well documented place in Western pharmacy, but modern controlled trials showing it treats any condition are essentially absent. Long traditional use is not proof that something works, and that applies to everything said below.

How does Balsam of Peru work?

Nobody has shown clearly what Balsam of Peru does in human skin. The best supported idea is simple: it forms a sticky, water resistant film that covers a sore or graze and keeps it moist.

Several of its chemicals kill bacteria and fungi in laboratory dishes. That is a test-tube result, not proof that it clears an infection on a person. Older texts also called it an expectorant (something that loosens chest mucus), but this was never tested properly.

Its one firmly proven biological effect is unwanted. It is a strong sensitiser, meaning it can teach your immune system to react to it, so later contact brings on an itchy rash.

What forms does Balsam of Peru come in?

Balsam of Peru is not usually sold on its own as a supplement. You are most likely to meet it as an ingredient in something else.

Common forms include ointments and creams for grazes, nappy rash, bedsores and haemorrhoids, usually at low strength. It also appears in some cough syrups and lozenges, in flavourings and perfumes, and in dental dressings.

A related, gentler material called Peru balsam oil or balsam extract is used in fragrance, because European cosmetic rules restrict the crude resin.

Where it comes from:

Indigenous peoples in Central America used the resin on wounds and for its scent long before Europeans arrived. Spanish traders shipped it to Europe from the 1500s onwards.

It entered the London, United States and German pharmacopoeias and stayed there for centuries, mostly as a wound and haemorrhoid ointment and a cough syrup flavouring.

Its reputation changed in the twentieth century, when skin doctors identified it as one of the leading causes of allergic contact rash and use began to fall.

What does Balsam of Peru help with?

• Minor grazes, cracked skin and slow-healing sores: This is the oldest and most common use, and it rests on tradition rather than trials. The resin makes a protective film over the sore and has germ-killing activity in laboratory tests. No modern controlled trial shows it heals wounds faster than a plain ointment, and because it is a strong allergen many skin doctors now advise against putting it on broken skin.
• Haemorrhoids (swollen veins around the back passage): Balsam of Peru is an ingredient in some older haemorrhoid ointments, combined with other substances. Any relief is likely to come from the greasy base soothing sore skin. There is no trial evidence that the balsam itself shrinks piles or stops bleeding, and sensitive skin in this area can react badly to it.
• Nappy rash and bedsores: Old barrier creams used it to cover and protect damaged skin. Modern practice has moved away from this, because inflamed or broken skin absorbs more of the resin and is more likely to become allergic to it. Plain zinc or petrolatum barriers do the same job without that risk.
• Cough and chest congestion: The balsam was a standard flavouring and supposed expectorant (mucus loosener) in cough syrups. The evidence is entirely traditional. Swallowing it regularly is no longer advised, because long internal use has been linked in older reports to kidney irritation and it can trigger a body-wide rash in people already allergic to it.
• Scabies and other skin parasites (historic use): One of its constituents, benzyl benzoate, is a genuine anti-scabies drug still used today as a purified medicine. That does not make the crude balsam a scabies treatment. Purified benzyl benzoate at a known strength is safer and better studied than an unstandardised resin.
• Dressings after dental surgery (historic use): Dentists once packed sockets and gum wounds with pastes containing Balsam of Peru. This was based on custom and on its sticky, aromatic nature. It has largely been replaced, partly because of allergy and partly because better dressings exist.

Which foods are rich in Balsam of Peru?

1. Cinnamon and cloves: contain the same cinnamates that cause cross-reaction
2. Vanilla and vanilla-flavoured sweets: share vanillin and related compounds
3. Cola and spiced soft drinks: commonly flavoured with balsam-type aromatics
4. Tomato products, ketchup and chutneys: a classic trigger in balsam-sensitive people
5. Citrus peel and marmalade: peel oils cross-react
6. Chocolate, chewing gum and flavoured toothpaste: frequent hidden sources

Practical Tips:

These foods matter only if a doctor has confirmed you are allergic to Balsam of Peru; a restricted diet is sometimes tried for a few weeks under medical supervision.

What are the side effects of Balsam of Peru?

• Itchy, red, sometimes blistering rash where it was applied (allergic contact dermatitis)
• Burning or stinging on broken skin
• Darkening or discolouration of treated skin
• Widespread rash, often in the armpits, groin or on the hands, in people already allergic who then eat cinnamon, vanilla or spiced foods
• Flare-up of eczema that was already there
• Mouth soreness or a burning tongue from flavoured syrups and lozenges
• Rarely, a severe whole-body allergic reaction with swelling and breathing trouble
• Kidney irritation reported in older accounts of long internal use

Good to know:

Allergic skin reaction is not a rare oddity here. Balsam of Peru is consistently among the top handful of allergens found in patch testing, with several percent of tested patients reacting.

Most reactions are an uncomfortable rash that clears once contact stops. Severe whole-body reactions are rare but have been reported.

How much Balsam of Peru should you take?

• Recommended daily: There is no established safe or effective dose for Balsam of Peru, and no health authority recommends taking it by mouth. When it appears in traditional skin ointments, it is usually between about 5 and 20 percent of the product. Follow the label on the finished product rather than trying to work out an amount yourself. Do not swallow the raw resin. Historic internal doses of a fraction of a gram are recorded in old pharmacy books, but they are not considered safe practice now.
• Best time of day: No time of day matters. Apply a skin product when the area is clean and dry, usually once or twice a day.
• With or without food: Not relevant for skin use. Internal use is not recommended, so there is no advice about food.
• Time to effect: Any soothing or protective effect from a skin ointment is immediate, because it is a barrier. An allergic rash, by contrast, usually appears 12 to 72 hours after contact, so a reaction on Wednesday may come from Monday's application.
• How long to take it: Use on the skin should be short. A few days is enough to tell whether a graze or sore is settling. Stop and reassess after about one week. Long or repeated skin contact is exactly what turns a person into someone allergic to it, so repeated courses are a bad idea.