Compare · Ingredients

Coal Tar vs Tea Tree Oil

Coal Tar: Helps reduce scaling and itching in psoriasis and some scalp products. Tea Tree Oil: A formulated 5% gel has limited evidence for mild acne.

Research updated 2026-10-25

Five medicated scalp products on white, including Amazon Basics tar gel, T+Plus, MG217, RoyceDerm and Nizoral

Five dark glass tea tree essential oil bottles with glass droppers and one green box on white

Which one?At a glance What it helps Diagrams Using both Strengths Results Safety How it works Products Questions

Which one is right for you?

Choose Coal Tar if…

Consider for scaly psoriasis or an appropriate scalp product if smell and staining are acceptable.

Thick, scaly psoriasis or scalp scale
Smell and staining are acceptable
Other scalp treatments haven’t helped

Choose Tea Tree Oil if…

Consider only a properly formulated acne product; standard acne medicines have broader evidence.

Mild acne
You prefer a botanical option
A properly diluted product

Alternatives, not combined

Can you use both?

Both are used for flaky scalp. Coal tar has stronger evidence; use one at a time.

At a glance

● Coal Tar

● Tea Tree Oil

Type

Anti-scaling medicine mixture

Essential oil mixture

What it does

Helps reduce scaling and itching in psoriasis and some scalp products.

A formulated 5% gel has limited evidence for mild acne.

Best for

Psoriasis; Scalp Psoriasis; Dandruff

Acne

Studied concentrations

1–5% crude coal tar preparations in older psoriasis trials; labels use different equivalents.

5% formulated gels in acne trials; do not apply undiluted essential oil.

When to use

Morning or night, as directed by the finished product.

Morning or night, as directed by the finished product.

Time to results

Often 8–12 weeks in small cosmetic studies; results may be subtle

Often 8–12 weeks in small cosmetic studies; results may be subtle

Irritation

Can irritate, stain skin or fabrics, and increase sun sensitivity; follow the label.

Can cause irritant or allergic dermatitis, especially when oxidized; never swallow it.

Sensitive skin

Choose a simple formula and test a small area first. Individual tolerance matters more than an ingredient’s reputation for being gentle.

Choose a simple formula and test a small area first. Individual tolerance matters more than an ingredient’s reputation for being gentle.

Available

Prescription or cosmetic status depends on the active, formula and country; check the label.

Cosmetic or OTC products; some high-strength procedures are separate treatments.

What it helps

Compare uses by strength of evidence. Evidence level describes confidence in a benefit, not its size.

Evidence level

Coal Tar

Tea Tree Oil

Moderate evidenceSome supportive research

Two thick, sharply bordered plaques on a knee on fair light skin. They are salmon-pink to red with loose silvery-white scale on top.

Psoriasis

Older controlled studies support some coal-tar preparations for plaque psoriasis.

—

Limited evidenceEarly or small studies

Parted hair on fair scalp skin showing a raised salmon-pink plaque topped with dry silvery-white scale, with a sharply drawn border against normal skin.

Scalp Psoriasis

Can help scale in appropriate scalp products; the cited body trials are indirect.

A part line in straight light hair, seen from above, on pale skin. White-gray flakes sit along the part and the scalp beneath them looks pink.

Dandruff

Used in labelled scalp products; evidence varies by formula.

Inflamed acne on light skin. The spots sit in a patch of pink, and the ring of redness around each one is easy to see. A few have a yellow-white head, and the skin between them is dry and flaking.

Acne

A small controlled trial found improvement with a formulated 5% gel.

Insufficient evidence

Salmon-pink patches with fine greasy yellowish scale in the crease beside the nose and through the eyebrow on fair skin, with soft edges that fade into normal skin.

Seborrheic Dermatitis

The reviewed sources do not establish this ingredient as a treatment for this concern.

Inflamed acne on light skin. The spots sit in a patch of pink, and the ring of redness around each one is easy to see. A few have a yellow-white head, and the skin between them is dry and flaking.

Acne

The reviewed sources do not establish this ingredient as a treatment for this concern.

AI-generated educational illustration of Perioral Dermatitis: 1. Perioral Dermatitis Header — Light Skin; Lighter skin. Not a clinical photograph.

Perioral Dermatitis

The reviewed sources do not establish this ingredient as a treatment for this concern.

A part line in straight light hair, seen from above, on pale skin. White-gray flakes sit along the part and the scalp beneath them looks pink.

Dandruff

The reviewed sources do not establish this ingredient as a treatment for this concern.

Sensitive Skin on light skin.

Sensitive Skin

Essential oil is not a treatment for sensitive skin and may cause allergy.

Athlete’s Foot: 1. Athlete’s Foot Header — Light Skin; Lighter skin.

Athlete’s Foot

The reviewed sources do not establish this ingredient as a treatment for this concern.

AI-generated educational illustration: Pink scratch marks and irritated bumps at the nape on light skin.

Head Lice

The reviewed sources do not establish this ingredient as a treatment for this concern.

How it works

Coal Tar mechanism diagram. Acts on rapid cell buildup: Coal tar affects abnormal epidermal activity. Helps reduce scale and itch: Response depends on the condition and formula. — Open full-size diagram
Diagram explanation and sources
Acts on rapid cell buildup: Coal tar affects abnormal epidermal activity. Helps reduce scale and itch: Response depends on the condition and formula.
Schematic illustration; not a measurement of skin penetration. Effects vary with ingredient identity and formulation.
Source 1 · Source 2

Tea Tree Oil mechanism diagram. Acts on microbes in lab tests: Terpenes can disrupt microbial membranes. Clinical effects depend on formula: Human acne evidence is limited. — Open full-size diagram
Diagram explanation and sources
Acts on microbes in lab tests: Terpenes can disrupt microbial membranes. Clinical effects depend on formula: Human acne evidence is limited.
Schematic illustration; not a measurement of skin penetration. Effects vary with ingredient identity and formulation.
Source 1 · Source 2

Using both in one routine

Built from where each one usually sits in a routine. Introduce one at a time.

Morning

Step 1

Cleanser

Step 2

Tea Tree OilMorning or night

Step 3

Moisturizer

Step 4

Sunscreen

Step 5

Coal TarAs directed

Night

Step 1

Cleanser

Step 2

Tea Tree OilMorning or night

Step 3

Moisturizer

Step 4

Coal TarAs directed

Strengths and forms

Concentrations

U.S. dandruff, seborrheic dermatitis and psoriasis products use 0.5–5% coal tar under specified labeling conditions. The percentage of a coal-tar solution is not necessarily the percentage of actual coal tar.

0.5–5%

U.S. labeled active range

A range for qualifying medicated products. Read the actual coal-tar equivalent when the label also names a coal-tar solution or extract.

Choosing a strength: Match shampoo, cream or ointment to the condition and body area. Look for the active concentration rather than comparing solution percentages.

Higher strengths: A larger solution percentage can be misleading. Stronger preparations may be less acceptable because of irritation, odor or staining.

Formula matters: Crude coal tar, coal-tar solutions and refined preparations differ. Their printed numbers should not be treated as identical doses.

Tea tree oil has limited clinical evidence for acne in formulated topical products. The studied concentration is not a reason to use undiluted essential oil.

5%

Acne gel studied

A small randomized placebo-controlled trial found improvement with a 5% tea tree oil gel over 45 days. This does not establish equivalence to standard acne medicines.

Choosing a strength: Choose a finished topical product with directions for use; stop if it causes irritation.

Higher strengths: Higher concentrations have not been established as more effective and may increase irritation or allergic reactions.

Formula matters: Tea tree oil must not be swallowed. Aged or oxidized oil can be more likely to cause an allergic reaction.

Forms

Shampoo · Ointment · Bath solution

Gel · Oil · Wash

When you’ll see results

Approximate windows, not promises.

● Coal Tar

● Tea Tree Oil

First few weeks

First few weeksAssess tolerance and texture; immediate softness can come from the base formula.

First few weeksAssess tolerance and texture; immediate softness can come from the base formula.

4–8 weeks

4–8 weeksSubtle changes may appear in some tested products; evidence varies.

4–8 weeksSubtle changes may appear in some tested products; evidence varies.

8–12 weeks

8–12 weeksCompare photographs in the same lighting and reassess benefit.

8–12 weeksCompare photographs in the same lighting and reassess benefit.

3–6 months

3–6 monthsPhotoaging trials often need several months; expect modest rather than dramatic change.

3–6 monthsPhotoaging trials often need several months; expect modest rather than dramatic change.

6–12 months

6–12 monthsLong-term evidence is limited for many cosmetic actives; continue only if useful.

6–12 monthsLong-term evidence is limited for many cosmetic actives; continue only if useful.

Safety and sensitive skin

Common reactions

Can irritate, stain skin or fabrics, and increase sun sensitivity; follow the label.

Can cause irritant or allergic dermatitis, especially when oxidized; never swallow it.

When to stop

Stop for persistent burning, swelling, blistering or a new rash. Seek urgent care for breathing difficulty or a severe allergic reaction.

Stop for persistent burning, swelling, blistering or a new rash. Seek urgent care for breathing difficulty or a severe allergic reaction.

Sensitive or inflamed skin

Choose a simple formula and test a small area first. Individual tolerance matters more than an ingredient’s reputation for being gentle.

Choose a simple formula and test a small area first. Individual tolerance matters more than an ingredient’s reputation for being gentle.

Important limits

Do not use a cosmetic product as a substitute for diagnosis of an unexplained, changing or persistent skin problem.

Do not use a cosmetic product as a substitute for diagnosis of an unexplained, changing or persistent skin problem.

Pregnancy

Coal tar is usually avoided in pregnancy and while breastfeeding; ask the clinician managing your pregnancy about alternatives.

Data are limited; ask the clinician managing your pregnancy.

How it works

In the skin

On the skin. The finished product delivers coal tar in a particular vehicle.

Entering skin. No single molecular mass. The 500 Da guideline cannot be applied to this whole ingredient family or mixture.

Conversion. No activation step is established as necessary for its intended topical role.

Skin response. A complex mixture affects abnormal skin-cell turnover and inflammation; no single active molecule defines it.

Additional effects. Proposed pathways do not establish a measured depth of delivery or clinical benefit beyond the studies cited.

On the skin. The finished product delivers tea tree oil in a particular vehicle.

Entering skin. No single molecular mass. The 500 Da guideline cannot be applied to this whole ingredient family or mixture.

Conversion. No activation step is established as necessary for its intended topical role.

Skin response. Its mixture has antimicrobial effects in laboratory tests; clinical benefit and allergy depend on the formula.

Additional effects. Proposed pathways do not establish a measured depth of delivery or clinical benefit beyond the studies cited.

Getting in

No single molecular mass. The 500 Da guideline cannot be applied to this whole ingredient family or mixture.

No single molecular mass. The 500 Da guideline cannot be applied to this whole ingredient family or mixture.

Product examples

Coal Tar

Soap Works Coal Tar Bar Soap — Coal tar works for psoriasis. This bar will not say how much is in it, and it is alkaline soap perfumed with essential oils, sold for eczema.
MG217 Psoriasis Gel — Coal tar 2% in an alcohol gel that washes out of hair. Flammable, and it contains fragrance.
Psoriasin Deep Moisturizing Ointment — Coal tar 2% in petrolatum. A real psoriasis drug, and the label says adults only.

Tea Tree Oil

SKIN1004 Madagascar Centella Tea-Trica Spot Cream

Common questions

Coal Tar:What should I choose coal tar for?

Consider for scaly psoriasis or an appropriate scalp product if smell and staining are acceptable.

Coal Tar:How strong is the evidence?

Small older trials studied particular tar preparations. Strengths expressed as crude tar and coal-tar solution are not directly interchangeable, and evidence cannot be generalized to every shampoo.

Tea Tree Oil:What should I choose tea tree oil for?

Consider only a properly formulated acne product; standard acne medicines have broader evidence.

Tea Tree Oil:How strong is the evidence?

A small placebo-controlled trial supports a 5% acne gel. Other trials compare active products; they do not establish benefit for every fungal infection, scalp condition or undiluted oil.

Sources

Sources and further reading

Dermapedia on YouTube