Coal Tar
Products with Coal Tar
Old Guard Scalp Therapy Tar Shampoo
Eight ingredients, no fragrance, no dye, and an active with a psoriasis indication that yeast-targeting shampoos cannot claim. Coal tar sits at the bottom of its permitted range here, which keeps the smell and staining manageable at the cost of some potency. If thick scaling is your problem rather than ordinary flaking, this is an unusually clean way to treat it.
Tar You'll Actually Keep Using Tar Gel Shampoo
The same 0.5 percent coal tar and the same psoriasis indication, thickened into a gel and given a lemon note — a formula engineered around the reason people quit tar, which is never efficacy. Worth it if smell is what has defeated you before. Not worth it if your scalp reacts to fragrance, since an identical unscented version exists.
The full coal tar guide
Coal tar has been used on inflamed skin since the nineteenth century, which is roughly a hundred and forty years longer than anyone understood why it worked.
That answer only arrived in 2013, when researchers showed the mechanism runs through the aryl hydrocarbon receptor — and in doing so handed a Victorian remedy a molecular explanation as modern as anything in the biologics era. It remains the least glamorous thing on the psoriasis shelf and one of the few that genuinely changes the disease rather than soothing around it.
Where the evidence stands, by concern
Evidence for an ingredient is not one grade — it differs concern by concern. Each row below was researched separately against regulatory approvals, clinical guidelines, and trials our team opened and verified; the band and dots rank how central coal tar is to treating that concern, from first-line therapy down to supportive care, at treatment-level doses and vehicles. A product's own grade weighs its actual formula.
How it's regulated in the US
FDA does not classify ingredients — it classifies products, by what they are sold to do. The same molecule can be a drug active in one product and a cosmetic ingredient in the next, and only the claim on the label decides which. What follows is a statement about that legal standing, not about whether it works — the evidence question is answered separately above.
OTC drug active Coal tar is a monograph active for all three of dandruff, seborrheic dermatitis and psoriasis — one of very few OTC ingredients permitted to say the word psoriasis on a label.
- dandruff, seborrheic dermatitis and psoriasis OTC monograph 0.5 to 5 percent
Generally recognized as safe and effective under an FDA order — marketed without FDA approval
Permitted label wording “Controls the symptoms of dandruff, seborrheic dermatitis and/or psoriasis”
The monograph requires the label to state the identity and concentration of the coal tar source as well as the coal tar concentration in the finished product — so '2 percent coal tar solution' and '2 percent coal tar' are different claims.
Coal tar is an FDA over-the-counter monograph active for dandruff, seborrheic dermatitis and psoriasis at 0.5-5%, and it appears by name in the 2021 joint AAD-NPF guidelines for topical psoriasis therapy. For psoriasis the evidence is strong and endpoint-matched — plaque clearance and PASI improvement with leave-on tar preparations, plus the Goeckerman regimen that pairs tar with phototherapy. For dandruff the picture is thinner than its long use suggests: verified trials sit at both ends of the monograph range, at 0.5% and 4%, with inconsistent comparative results, so the dose-effect relationship within that range is not actually established. The safety question that drove tar off many shelves has also been studied directly — a cohort of 13,200 psoriasis and eczema patients followed for a median of 21 years found no increased risk of skin cancer or non-skin malignancy after dermatological coal tar treatment.
How it works
Coal tar is not a molecule but a mixture — thousands of compounds distilled from bituminous coal, among them a large population of polycyclic aromatic hydrocarbons. Those hydrocarbons are the working part, and their target is the aryl hydrocarbon receptor, a sensor sitting inside keratinocytes that evolved to detect environmental chemicals and adjust the cell's behaviour accordingly. When coal tar activates that receptor, the keratinocyte turns on its terminal differentiation program. Barrier proteins that psoriatic and eczematous skin underproduces — filaggrin, involucrin, hornerin — come back up, in one study restoring filaggrin in genetically deficient keratinocytes to normal levels. Knocking the receptor down with siRNA abolishes the effect entirely, which is about as clean a demonstration of a mechanism as topical dermatology gets. Coal tar also counteracts the Th2 inflammatory signalling that suppresses those same barrier genes. On top of that sits an older, coarser action: tar is antiproliferative and keratoplastic, slowing the runaway keratinocyte division that builds a psoriatic plaque and helping the accumulated scale detach. That combination — pushing cells toward proper maturation while braking their multiplication — is why plaques flatten rather than merely stop itching, and why the effect outlasts the application in a way an emollient's never does.
Key benefits
- Genuinely antiproliferative — flattens psoriatic plaques rather than only soothing
- Restores barrier proteins including filaggrin via aryl hydrocarbon receptor activation
- Named in the joint AAD-NPF topical psoriasis guidelines
- Available over the counter at treatment strength, unlike most effective antipsoriatics
- Long remission periods reported when paired with phototherapy
- Inexpensive relative to nearly every alternative for chronic plaque disease
Concentration & usage
The US monograph range is 0.5-5% coal tar in shampoos, creams and bath solutions; crude coal tar up to 5% in ointment is the classic leave-on preparation, with higher strengths used inside supervised Goeckerman regimens. Contact time and concentration both matter, and the strongest psoriasis evidence belongs to leave-on preparations rather than brief-contact shampoo — though shampoo has its own scalp-psoriasis data. Labels often say 'coal tar solution' or 'liquor carbonis detergens' rather than a percentage of tar itself; those are alcoholic extracts, and the tar equivalent is a fraction of the stated solution percentage, so a 5% LCD product is not a 5% coal tar product.
Who it's for & who should be cautious
Who it's for
Plaque psoriasis is where coal tar earns its keep, particularly for people who want a steroid-sparing option for maintenance or who have plaques on the scalp that resist gentler shampoos. It suits anyone willing to trade cosmetic pleasantness for a treatment that actually alters plaque behaviour, and it remains useful in combination with phototherapy under dermatological supervision. Scalp seborrheic dermatitis with thick, adherent scale is a reasonable secondary use, though the dandruff evidence is weaker than the psoriasis evidence.
Who should be cautious
Coal tar is photosensitizing — it makes treated skin markedly more vulnerable to UV, which is exactly why supervised regimens pair it deliberately with measured light exposure and why unsupervised sun exposure after application can cause a painful burn. Do not use it on acutely inflamed, broken, weeping or infected skin, or in the folds and genital area. Pregnancy and breastfeeding are usually reasons to choose something else, given the polycyclic aromatic hydrocarbon content and the absence of reassuring data. It stains fabric, hair and bathroom surfaces permanently, smells strongly, and can cause folliculitis with prolonged use. People with light hair should expect discoloration from tar shampoos.
Pairs with & conflicts
Pairs well with: Salicylic Acid (BHA), Urea (Carbamide), Petrolatum (Petroleum Jelly), Ceramides, Colloidal Oatmeal
Myths & facts
Myth: Coal tar causes cancer, which is why doctors stopped using it.
Reality: The concern is real in origin — occupational exposure to coal tar in industrial settings is genuinely carcinogenic, and that history is why many dermatologists quietly dropped it. But the question has been studied in the actual therapeutic setting: a cohort of 13,200 psoriasis and eczema patients followed for a median of 21 years found no increased risk of skin cancer or of malignancy elsewhere after dermatological coal tar treatment. The dose, duration and route of an industrial exposure are not those of a scalp shampoo, and treating them as equivalent is the error.
Myth: Coal tar just softens and lifts the scale, like a heavy moisturizer does.
Reality: It does loosen scale, but that is the least of what it does. Coal tar activates the aryl hydrocarbon receptor in keratinocytes, which switches the terminal differentiation program back on and restores barrier proteins including filaggrin — an effect that disappears entirely when the receptor is knocked down. It is also antiproliferative. That is a disease-modifying action no emollient reproduces.
Myth: A tar shampoo works as well for psoriasis as a tar ointment.
Reality: The efficacy is concentration- and contact-time-dependent, and the strong psoriasis evidence belongs to leave-on preparations. Shampoo has its own evidence for scalp psoriasis specifically, and it is the practical choice for a hairy site, but a two-minute rinse-off is not the same intervention as an ointment worn overnight, and expectations should be set accordingly.
Frequently asked questions
How long does coal tar take to work on psoriasis plaques?
Slowly, by modern standards. Expect several weeks of consistent use before plaques visibly flatten, with scale reduction usually coming first. This is not a treatment that rewards impatience, and stopping at two weeks because nothing dramatic has happened is the most common way people conclude it does not work for them.
Why do I have to avoid the sun after applying coal tar?
Coal tar is photosensitizing — it lowers the threshold at which UV burns treated skin. Supervised Goeckerman regimens exploit this deliberately with measured light doses, but an unmeasured afternoon outdoors after application can produce a serious burn. Apply at night where possible, wash it off before sun exposure, and use sunscreen on treated areas.
Will coal tar shampoo stain my hair?
It can, particularly light, grey, bleached or chemically treated hair, where even slight residue shows as a yellowish cast. Thorough rinsing prevents most of it. Tar also stains towels, pillowcases, tiles and bath surfaces, so a dedicated dark towel is a practical precaution rather than an excess of caution.
Is coal tar better than a steroid for scalp psoriasis?
They do different jobs. A topical steroid clears faster and is more comfortable to use; coal tar works more slowly but is not limited by the skin-thinning that caps long-term steroid use, which makes it useful for maintenance between steroid courses. Many dermatologists use them in sequence rather than choosing one.
What is the difference between coal tar and 'coal tar solution' or LCD on a label?
Coal tar solution — also written as liquor carbonis detergens — is an alcoholic extract containing roughly a fifth as much tar as the stated percentage. A product listing 5% coal tar solution therefore delivers around 1% coal tar, not 5%. It matters when comparing products, and the two are frequently conflated on packaging.