Pine Tar Soap for Eczema and Psoriasis: What the Research Actually Says

Pine tar has been used on skin for over 2,000 years. That's not marketing copy — that's documented medical history going back to Hippocrates. But longevity alone doesn't make something effective. Snake oil has been around a long time too.

What separates pine tar from most traditional remedies is that it's actually held up when researchers looked at it properly. There's peer-reviewed clinical research, a randomized controlled trial, and recognition from major dermatological organizations. If you've been dealing with eczema or psoriasis and wondering whether pine tar soap is worth trying, here's what the science actually shows.

What Is Pine Tar and How Does It Work?

Pine tar is produced by burning pine wood at high heat in a low-oxygen environment — a process called destructive distillation. The result is a dark, resinous substance rich in phenolic compounds, turpenes, and resin acids. These aren't inert ingredients. They're the active components responsible for pine tar's therapeutic effects on skin.

According to a 2017 peer-reviewed review published in the Australasian Journal of Dermatology by Barnes and Greive — one of the most comprehensive scientific assessments of pine tar to date — pine tar works through a specific mechanism: it reduces DNA synthesis and mitotic activity in skin cells, which promotes a return to normal keratinization. In plain English, it slows down the abnormal cell turnover that drives conditions like psoriasis and eczema, while helping skin rebuild its normal structure. The same review confirmed that pine tar is antipruritic (reduces itching), anti-inflammatory, antibacterial, and antifungal. Read the full review at PubMed Central.

The Clinical Evidence: What Studies Actually Show

The most significant recent study on pine tar and eczema is a 2022 randomized controlled trial (RCT) published in the Journal of Dermatological Treatment, conducted by researchers at the Chinese University of Hong Kong. This is the kind of study that carries real weight — investigator-blinded, crossover design, with standardized outcome measures used across dermatology research worldwide.

The trial assessed children with moderate-to-severe atopic dermatitis (eczema). Patients were assigned to bathe with pine tar bath oil for one month, then switch to a vehicle-only bath oil, with a washout period between. Researchers measured disease severity using the SCORAD index (Scoring Atopic Dermatitis) and POEM (Patient-Oriented Eczema Measure), as well as blood IgE levels and Staphylococcus aureus colonization — a bacteria that commonly worsens eczema flare-ups.

The results were statistically significant across multiple measures. Patients using pine tar showed meaningful improvements in total SCORAD scores, itch intensity, and disease extent. IgE levels dropped. Staphylococcus aureus colonization — which drives a lot of eczema severity — was reduced. The researchers' conclusion: bathing with pine tar is an efficacious and recommendable adjuvant practice for patients with atopic dermatitis. Read the study on PubMed.

What Dermatological Organizations Say

Pine tar and coal tar aren't just folk remedies tolerated by mainstream medicine — they're recognized therapeutic agents. The National Psoriasis Foundation lists tar as an over-the-counter treatment option, noting that it can help slow the rapid growth of skin cells and reduce itching, inflammation, and scaling associated with psoriasis. See the National Psoriasis Foundation's OTC treatment page.

The Barnes and Greive review also notes that pine tar has been available over-the-counter in Australia as a recognized therapeutic product since 1953 — it's not a fringe treatment. It's been sitting in a regulatory framework as a legitimate skin treatment for over 70 years.

Pine Tar vs. Coal Tar: Why It Matters for Eczema and Psoriasis

Both are used for similar conditions, but they're not the same thing and they don't carry the same risk profile. Coal tar is a byproduct of coal processing and contains polycyclic aromatic hydrocarbons (PAHs) at levels high enough to raise concerns about long-term use. Products containing more than 0.5% coal tar require a cancer warning label in California.

Pine tar contains PAHs at dramatically lower concentrations. The Barnes and Greive review specifically confirms that PAH levels in pine tar are far lower than in coal tar, and that pine tar has not been shown to be mutagenic. Unlike coal tar, pine tar also doesn't cause photosensitization — meaning it doesn't make your skin more vulnerable to sun damage, which is a documented side effect of coal tar use.

For daily use — which is what you're doing with a bar soap — pine tar is the more sensible choice. It delivers similar anti-inflammatory and antipruritic benefits with a significantly cleaner safety profile.

What to Look for in a Pine Tar Soap if You Have Eczema or Psoriasis

The research is clear that pine tar works. But the bar you buy matters. Here's what to look for:

Real pine tar content. Some bars use so little pine tar it's effectively decorative. The active properties come from actual pine tar — not a trace amount added for marketing purposes. Look for pine tar listed near the top of the ingredient list, not buried at the bottom.

No synthetic fragrance. This is non-negotiable for eczema and psoriasis. "Fragrance" on an ingredient label is a catch-all term that can include hundreds of synthetic chemicals, some of which are documented skin sensitizers and contact allergens. Synthetic fragrance in a soap marketed for sensitive skin is contradictory at best. Look for essential oils listed by name, or no scent at all.

Cold process, real soap base. Real cold process soap made from saponified oils preserves glycerin — a natural byproduct of saponification that helps maintain skin moisture. Commercial detergent bars strip glycerin out and replace it with synthetic alternatives. For compromised skin, this difference is meaningful.

Adequate cure time. Cold process soap needs to cure — ideally six weeks or more. A rushed bar is softer, lathers less efficiently, and doesn't perform the same way. It also won't last as long.

Wild Timber's Pine Tar bar checks every one of these boxes. It's cold process, cured a minimum of six weeks, made with saponified oils of olive, coconut, and avocado, and contains no synthetic fragrance of any kind. Pine tar is listed prominently in the ingredients — not as a token addition. It also contains activated charcoal and kaolin clay for additional cleansing without harshness. $8 for a 5oz bar.

This soap exists because eczema is personal to us. Our co-founder's son has dealt with severe eczema for 18 years. That's not a tagline — it's the reason Wild Timber was built the way it was.

A Note on Managing Expectations

Pine tar soap is not a cure for eczema or psoriasis. Both are chronic conditions with complex causes, and no single product resolves them entirely. What pine tar soap can do — as the research shows — is meaningfully reduce inflammation, itching, and bacterial colonization as part of a broader skincare routine. It's a tool, not a treatment. If you have severe or worsening symptoms, see a dermatologist. Pine tar soap works best as a daily maintenance choice, not a crisis intervention.

Frequently Asked Questions

Is pine tar soap good for eczema?

Yes, with evidence to back it up. A 2022 randomized controlled trial published in the Journal of Dermatological Treatment found statistically significant improvements in eczema severity scores, itching, and Staphylococcus aureus colonization in patients who used pine tar for bathing. A 2017 peer-reviewed review in the Australasian Journal of Dermatology confirmed pine tar's anti-inflammatory and antipruritic properties. It won't cure eczema, but as a daily soap it's one of the more research-supported choices available over the counter.

Is pine tar soap good for psoriasis?

Yes. The National Psoriasis Foundation recognizes tar as an OTC treatment option for psoriasis, citing its ability to slow abnormal skin cell growth and reduce itching, inflammation, and scaling. Pine tar works on psoriasis through its keratolytic effect — softening and loosening thickened skin — combined with its anti-inflammatory action on the underlying condition driving that buildup.

Is pine tar soap safe to use daily?

Yes, for most people. Pine tar has a long history of safe topical use and a significantly cleaner safety profile than coal tar. The 2022 RCT recorded no product-related serious adverse events. As with any product on compromised skin, patch testing first is sensible, and if you're managing a diagnosed skin condition you should coordinate with your dermatologist on any additions to your routine.

What's the difference between pine tar and coal tar for skin conditions?

Both are used for eczema and psoriasis, but pine tar is derived from pine wood and carries a lower concentration of polycyclic aromatic hydrocarbons (PAHs) — the compounds that raise safety concerns with long-term coal tar use. Pine tar also doesn't cause photosensitization, which is a documented side effect of coal tar. For a daily-use soap, pine tar is the more appropriate choice for most people.