What is Tar?

Tar here means pine tar, a thick, dark, smoky-smelling liquid made from pine wood. Most of it comes from the longleaf pine, Pinus palustris, and its close relatives. Wood is heated in a low-oxygen kiln until the tar runs out.

Today it is used on the skin. Soaps, shampoos, bath oils and salves are the usual forms. People reach for them for itch, flaking and scaly rashes.

Older American medicine also gave tar by mouth for coughs, as "tar water" or tar syrup. That practice is obsolete. No safe amount for swallowing is given on this page.

The evidence verdict: human trials of pine tar are few, small and old. It may ease itch and scaling for some people, and it is not a cure for any skin disease. A long record of traditional use is not proof that something works, and it is not proof that it is safe.

How does Tar work?

No one has pinned down how pine tar works on skin. The main idea is that it slows skin cells that are dividing too fast. That matters in psoriasis, where scaling builds up.

In laboratory work, tar compounds appear to slow skin cell growth. Most of that work used coal tar, which has been studied far more. Whether pine tar does the same on human skin is not settled.

Tar also seems to dull itch. In animal studies, tar compounds appear to quiet nerve signals linked to itching. Human testing of pine tar for this is thin.

Tar dries and coats the skin surface. In test tubes it slows some bacteria and fungi. That does not show it clears a skin infection in real life.

Tar makes skin more sensitive to sunlight. This is a known effect, not a theory. Skin doctors have long paired tar with careful, supervised light treatment for psoriasis.

What forms does Tar come in?

Skin products are what you will actually find for sale.

- Pine tar soap bars, used as a body or face wash.

- Pine tar shampoos for dandruff and an itchy scalp.

- Bath oils and bath liquids, sold mainly in Australia and parts of Europe.

- Ointments and salves, blended with wax or petrolatum (petroleum jelly).

- Raw pine tar in tins, sold for animal hooves, rope and wood. This grade is not meant for human skin.

Tar water and tar syrup were once taken by mouth. They are no longer sold as medicines, and this page gives no amount for them.

Coal tar is a different product from a different source. It is stronger and richer in PAHs. The two are not swapped for each other.

Where it comes from:

Pine tar has a long, well-recorded place in American folk and Eclectic medicine. Eclectic doctors of the 1800s listed it for coughs, chest complaints and stubborn skin disease. Tar water and tar syrup were common household remedies.

The longleaf pine belt of the American South was the centre of the trade. Settlers burned the resinous wood in earth kilns to draw off tar and pitch. The same tar sealed ships' ropes and hulls.

Farmers used it on animals' hooves and on cuts. Its sharp smell was thought to keep flies off. Much of this use was practical rather than medical.

By the 1900s the medical use narrowed to the skin. Tar soaps and shampoos stayed on shelves. Doctors dropped the swallowed forms as safer cough medicines arrived.

This section records what was done in the past. It is not a suggestion to copy it.

What does Tar help with?

• Eczema (atopic dermatitis, an itchy inflamed rash): Folk and Eclectic use set tar against itchy, scaly rashes. A few small, mostly older studies of pine tar bath products report less itch and scaling. The trials are small and weak, so this is suggestive, not proven.
• Psoriasis (thick scaly patches of skin): Tar is one of the oldest treatments for psoriasis. Almost all the good trial evidence is for coal tar, not pine tar. Pine tar may soften scaling, but it has not been tested the same way.
• Dandruff and seborrhoeic dermatitis (a flaky, itchy scalp): Pine tar shampoos are widely sold for flaking and scalp itch. Users often report fewer flakes, and tar's drying action makes that plausible. Good trials comparing pine tar with standard anti-dandruff shampoos are missing.
• General itchy, dry, scaly skin: Tar has a long record as an anti-itch wash. In animal studies, tar compounds appear to dull itch signals. Human evidence for pine tar on its own is thin.
• Cough and chest complaints (historical use only): Eclectic practice gave tar water and tar syrup for coughs. No modern trial supports this. Swallowing tar is not a safe modern practice, and no amount is given here.
• Minor sores and skin blemishes (historical use only): Tar salves were put on sores and infected-looking skin. In test tubes, tar compounds slow some bacteria and fungi. Tar stings and irritates broken skin, so it is not used on open wounds today.

What are the side effects of Tar?

• Stinging or burning where it is applied
• Dryness, cracking or peeling skin
• Redness and irritation
• Allergic rash, sometimes days after use
• Tar folliculitis (pimple-like bumps around hair roots)
• Easy sunburn on treated skin
• Temporary darkening of the skin
• Staining of hair, nails, towels, clothes and baths
• Strong smoky smell that lingers
• Worse symptoms on broken or weeping skin

Good to know:

Mild effects are common. Dryness, stinging, smell and staining are the usual complaints, and they settle after you stop.

Allergy to tar or pine resin is less common but real. It shows as a spreading, itchy rash that gets worse with each use.

Sunburn is the effect people underestimate. Tar-treated skin can burn fast in sunlight.

The cancer question comes from PAHs, the tar chemicals that cause tumours in animals. Long-term studies of tar used on skin have not shown a clear rise in human cancer. The data for pine tar in particular are limited, which is why long, heavy, unsupervised use is discouraged.

How much Tar should you take?

• Recommended daily: This page gives label norms only. It is not advice for you. Pine tar soap labels usually say to wash with it once a day. Shampoo labels often say to lather, leave it on the scalp for a few minutes, then rinse well. Many shampoo labels suggest two or three washes a week. Bath product labels give a small capful for a full tub. Ointments are usually described as a thin layer on the affected patch. No amount for swallowing is given here, in any form. Tar water and tar syrup belong to history, not to current use. Raw tar sold for hooves or rope is not a skin product.
• Best time of day: Evening use suits most people. Tar makes skin more sensitive to sunlight, so applying at night lowers the burn risk. Wash it off before you go out in strong sun. Cover treated skin or use sunscreen. Do not use a sunbed while you are using tar. For shampoo, timing matters less, since it is rinsed out.
• With or without food: Food is not relevant. Pine tar is used on the skin and scalp only. Do not swallow it with or without food. Keep tar products away from the mouth, the eyes and food surfaces. Wash your hands after use.
• Time to effect: Expect slow change, if any. People who respond often notice less itch within a few days to two weeks. Scaling and thick patches take longer, often three to four weeks. Many people see no useful change at all. Pine tar does not clear eczema or psoriasis, and relapse after stopping is common.
• How long to take it: Short courses are the normal pattern. Soaps and shampoos are often used for a few weeks, then stopped or cut back. If itch or flaking has not shifted after about four weeks, that is a signal to see a doctor. Carrying on for months, over large areas, without medical advice is not sensible. Some people with psoriasis use tar long term under a dermatologist (skin doctor). That is a supervised decision, not a self-care one.