Clascoterone Overview, Dosing & Safety | Peptide Database

Clascoterone (CB-03-01)

Topical Androgen Receptor Inhibitor | Acne & Hair Loss

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Clascoterone (cortexolone 17-alpha-propionate) is a first-in-class topical androgen receptor inhibitor developed by Cassiopea SpA. In August 2020, the FDA approved Winlevi (clascoterone cream 1%) for the treatment of acne vulgaris in patients aged 12 and older, making it the first new mechanism of action for acne treatment in nearly four decades and the first topical anti-androgen approved for acne in the United States. Clascoterone is also under development as Breezula (clascoterone solution 7.5%) for androgenetic alopecia, where it has completed Phase 3 clinical trials. The compound works by competitively inhibiting androgen receptor activation at the site of application -- the sebaceous gland for acne and the hair follicle for androgenetic alopecia -- without producing the systemic anti-androgenic effects associated with oral anti-androgens such as spironolactone or cyproterone acetate. Its steroidal structure allows it to fit precisely into the androgen receptor binding pocket, and its rapid local metabolism to cortexolone (an inactive metabolite) limits systemic exposure. This pharmacological profile makes clascoterone suitable for use in both men and women, unlike systemic anti-androgens which carry risks of feminization in male patients.

Clascoterone acts as a competitive antagonist of the androgen receptor (AR). When applied topically, it penetrates the skin and binds directly to androgen receptors in target tissues -- sebaceous glands (for acne) and dermal papilla cells of hair follicles (for alopecia). By occupying the AR binding site, clascoterone prevents dihydrotestosterone (DHT) and testosterone from activating the receptor and initiating the downstream signaling cascade that drives sebum overproduction and hair follicle miniaturization. Structurally, clascoterone is a synthetic derivative of cortexolone (11-deoxycortisol), modified with a 17-alpha-propionate ester. This structural design serves two purposes: the steroidal backbone provides high binding affinity for the androgen receptor, while the ester group is rapidly cleaved by local esterases in the skin, converting clascoterone to cortexolone, which has negligible androgen receptor binding. This built-in metabolic inactivation ensures that any compound reaching systemic circulation is pharmacologically inactive, confining the anti-androgenic effect to the treatment site. In clinical studies, clascoterone showed no meaningful impact on systemic hormone levels including testosterone, DHT, luteinizing hormone, or follicle-stimulating hormone at therapeutic doses, confirming its local mechanism of action.

Molecular Data

Research Indications

Winlevi (clascoterone cream 1%) is FDA-approved for the topical treatment of acne vulgaris in patients 12 years and older. Phase 3 trials demonstrated statistically significant reductions in inflammatory and non-inflammatory lesion counts compared to vehicle, with an Investigator Global Assessment success rate significantly higher than placebo.

Particularly relevant for women with androgen-driven acne who cannot tolerate or prefer to avoid systemic anti-androgens like spironolactone. Provides targeted anti-androgen activity at the sebaceous gland without the systemic effects, menstrual irregularities, or contraindication in pregnancy associated with oral anti-androgens.

Breezula (clascoterone solution 7.5%) has completed Phase 3 clinical trials for androgenetic alopecia in men. Trial results showed improvements in target area hair count compared to vehicle. Regulatory submission is pending. The topical anti-androgen approach offers a potential alternative to systemic 5-alpha reductase inhibitors for men concerned about systemic side effects.

The favorable safety profile and lack of systemic anti-androgenic effects make clascoterone a candidate for female androgenetic alopecia, where systemic anti-androgens carry teratogenic risks. Clinical data in women for this indication is still being developed.

Dosing Protocols

Clascoterone is available in two topical formulations targeting different indications. Winlevi (clascoterone cream 1%) is commercially available by prescription for acne vulgaris. Breezula (clascoterone solution 7.5%) is under regulatory review for androgenetic alopecia. Both formulations are designed for direct application to the affected area, where the compound acts locally before being metabolized to inactive cortexolone.

Acne treatment (FDA-approved)

Clascoterone 1% cream (Winlevi)

Twice daily (morning and evening)

Apply a thin layer to affected areas of the face after cleansing

Androgenetic alopecia treatment (investigational)

Clascoterone 7.5% solution (Breezula)

Once daily

Apply approximately 1mL to affected areas of the scalp

Interactions

What to Expect

Side Effects & Safety

Common Side Effects

Application site irritation, redness, or dryness

Pruritus (itching) at the application site

Contact dermatitis in sensitive individuals

Stop Signs - Discontinue if:

Severe or worsening skin irritation, blistering, or open sores at application site

Allergic reaction (facial swelling, hives, difficulty breathing)

Any unexplained systemic symptoms that correlate with use

Contraindications

Known hypersensitivity to clascoterone or any component of the formulation

Women who are pregnant or planning to become pregnant (anti-androgens carry theoretical teratogenic risk)

Women who are breastfeeding (safety not established)

Active skin infections at the intended application site

Quality Checklist

Good Signs

Obtained via prescription from a licensed healthcare provider (Winlevi)

Commercial product in original sealed packaging with valid expiration date

Stored according to label instructions at controlled room temperature

Cream or solution is uniform in consistency without discoloration or separation

Warning Signs

Product obtained from an international pharmacy without proper verification

Approaching or past expiration date

Packaging appears tampered with or resealed

Bad Signs

Product sourced from unregulated or unknown suppliers

Compounded formulation without certificate of analysis or proper labeling

Cream or solution that has changed color, separated, or developed an unusual odor

Product sold without a prescription when one is legally required

Frequently Asked Questions

Is clascoterone topical better than oral spironolactone for hormonal acne?

Clascoterone offers advantages: it blocks androgen receptors locally at sebaceous glands without systemic anti-androgenic effects, so it can be used safely in men and women without causing feminization or menstrual irregularities. Spironolactone blocks androgen receptors systemically, causing side effects that limit use in men. Clascoterone is FDA-approved for acne.

Can men use clascoterone cream without feminization?

Yes. Because clascoterone works locally at the skin and is rapidly metabolized to inactive cortexolone, it produces no clinically meaningful systemic anti-androgenic effects. Serum testosterone, DHT, LH, and FSH remain normal. This is a key advantage for male acne sufferers.

How long until I see results from clascoterone cream?

Inflammatory and non-inflammatory lesion counts begin improving by week 12 based on Phase 3 trials. Full clinical benefit typically appears between months 3-6. Clascoterone for hair loss requires 6-12 months of use to assess efficacy, as it targets follicular miniaturization which reverses slowly.

Can I use clascoterone and minoxidil together for hair loss?

Yes. This is synergistic. Clascoterone blocks androgen action at the follicle (addressing the DHT-driven miniaturization), while minoxidil stimulates follicular blood flow and promotes growth. The two address hair loss through complementary mechanisms and should be applied at separate times to ensure proper absorption.

References

Comprehensive review of the clinical development program for clascoterone cream 1% in acne vulgaris. Summarized Phase 2 and Phase 3 data demonstrating significant reductions in inflammatory and non-inflammatory lesion counts versus vehicle, with a favorable safety profile and no meaningful systemic anti-androgenic effects.

Pivotal Phase 3 trials (CB-03-01/25 and CB-03-01/26) involving over 1,400 patients demonstrated that clascoterone cream 1% applied twice daily was significantly superior to vehicle in achieving treatment success (IGA score of 0 or 1 with at least a 2-grade improvement) and reducing both inflammatory and non-inflammatory lesion counts at week 12.

Phase 2 trial of clascoterone solution 7.5% in men with androgenetic alopecia showed dose-dependent increases in target area hair count compared to vehicle after 6 months of once-daily application. The treatment was well tolerated with no clinically significant effects on serum hormone levels.

Characterized the mechanism of action of clascoterone (CB-03-01) in dermal papilla cells. Demonstrated competitive androgen receptor antagonism with high binding affinity and confirmed rapid metabolism to cortexolone, an inactive metabolite, supporting the rationale for topical use with minimal systemic effects.

Related Peptides

Clascoterone and finasteride address androgen-driven hair loss through complementary mechanisms. Finasteride inhibits 5-alpha reductase to reduce systemic DHT production, while clascoterone blocks remaining androgens from activating the receptor at the follicle. This dual approach targets both the ligand supply and the receptor activation, potentially providing greater efficacy than either agent alone.

Minoxidil promotes hair growth via vasodilation and potassium channel activation, a mechanism entirely independent of androgen signaling. Combining clascoterone (which blocks androgen receptor activation at the follicle) with minoxidil (which stimulates follicular blood flow and growth signaling) addresses hair loss from two distinct pathways. The two topicals should be applied at separate times to ensure proper absorption of each.

Disclaimer

This information is for educational and research purposes only. Consult a healthcare professional before use.