Does clascoterone have any side effects?

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    Does clascoterone have any side effects?

    Clascoterone (brand name Winlevi) is a prescription topical cream approved by the U.S. Food and Drug Administration (FDA) in August 2020 for the treatment of moderate to severe acne in individuals aged 12 years and older. It represents a breakthrough as the first topical anti-androgen treatment that directly targets hormone receptors in the skin, helping to reduce oil (sebum) production and inflammation without the systemic effects often seen with oral medications. But does this innovative treatment come without side effects? The answer is more nuanced. Let’s explore the evidence in detail.

    Mild skin reactions are the norm—what patients usually experience

    Most people who use clascoterone experience only minor and localized side effects. These reactions generally occur in the area where the cream is applied and include symptoms such as redness (also called erythema), itching (pruritus), dryness, flaking or scaling, and a sensation of stinging or burning. These are typical responses seen in approximately 7–12% of users in clinical studies.

    Some individuals may also notice minor swelling (edema), thinning of the skin (atrophy), the appearance of tiny visible blood vessels (telangiectasia), or red stretch marks (striae rubrae). These effects are usually transient and mild. Interestingly, the frequency of these events is similar to those observed in people who used a placebo cream, indicating that they are part of the natural sensitivity of the skin to topical treatments. For the majority of users, clascoterone is very well tolerated. These mild skin reactions tend to diminish over time as the skin adapts to the treatment. For those who have previously used retinoids or benzoyl peroxide, the tolerability profile of clascoterone is often found to be milder.

    What about more serious risks—should you be concerned?

    Rare but potentially important systemic side effects have been observed, especially in certain populations. Among pediatric patients, particularly those aged 9 to 11, suppression of the hypothalamic-pituitary-adrenal (HPA) axis has been documented. This is a hormonal feedback system that controls stress response and various metabolic functions. In one study, up to 10% of children using high doses of clascoterone showed temporary suppression of this axis. Fortunately, this condition resolved once the cream was discontinued. Additionally, elevated blood potassium levels, a condition called hyperkalemia, was reported in around 5% of people using clascoterone. However, a nearly identical percentage (4%) was observed in the placebo group, suggesting that the medication itself may not be the direct cause in typical cases. There have been no confirmed reports of clascoterone causing adrenal gland failure or long-term hormonal imbalances in the general population. Serious adverse effects seem to be rare, and when they do occur, they are usually linked to using high doses over large areas of the body, especially in young children who have more sensitive skin and a higher surface area-to-body weight ratio.

    Evidence from up to 12 months of real-world use

    Real-world evidence helps validate how a treatment behaves outside the tightly controlled setting of a clinical trial. A long-term study published in 2023 monitored the safety of clascoterone over a nine-month period in 600 patients aged 12 and older. This open-label extension allowed researchers to observe side effects over time in those who had previously participated in shorter studies.

    The findings were encouraging: about 18.1% of participants reported adverse events, but these included both clascoterone users and those using the vehicle cream (placebo). The most common issues remained skin-related, such as redness (about 8%) and dryness (about 10%). Importantly, these side effects were not severe enough in most cases to require stopping the treatment. This long-term data provides reassurance that clascoterone’s safety profile does not significantly change with extended use. No new or unexpected side effects were identified, and participants were able to maintain treatment without serious complications.

    But can sensitive or damaged skin pose additional risks?

    People who have pre-existing skin conditions like eczema, rosacea, or very sensitive skin might wonder whether clascoterone is appropriate for them. It’s important to note that individuals with these skin types were largely excluded from major clinical trials. That means we have limited data about how this population may react. That said, clascoterone is formulated without alcohol, fragrances, or other known skin irritants. A small but informative 2025 study examined the effect of clascoterone on skin hydration and barrier function in adults with acne-prone skin. Over two weeks, participants actually experienced improved skin moisturization and no increase in transepidermal water loss (a sign of skin barrier integrity).

    This suggests that the formulation is gentle, even on vulnerable skin. However, anyone with known skin sensitivities should perform a patch test—applying a small amount to a limited area—to see how their skin reacts before using the product more broadly.

    Answering the initial question: yes—with context

    Yes, it does. However, these are mostly minor, predictable, and limited to the area of application. Users may experience skin redness, dryness, itching, or a burning sensation—most of which resolve with continued use or adjustment of application frequency. Rare but more serious side effects like hormonal axis suppression or elevated potassium levels have occurred, but almost exclusively under extreme or off-label use, especially in pediatric populations.

    For typical use—once or twice daily in patients 12 and older and applied to limited areas of the face—serious risks are very low. Ongoing studies and post-marketing surveillance continue to support a favorable safety profile, even with prolonged use.

    User Experiences: Side Effects of Clascoterone

    Clascoterone, also known as CB-03-01 or under the brand name Breezula (for hair loss) and Winlevi (for acne), has attracted growing interest in the Tressless community as a topical anti-androgen that may avoid the systemic side effects associated with oral medications like finasteride or dutasteride. But what are users actually experiencing when they try it? Many users report that clascoterone is well tolerated, especially when compared to more systemic anti-androgens. In a discussion from a user who had adverse effects with low-dose topical finasteride, clascoterone was being seriously considered as a replacement due to its minimal reported side effects and localized action.

    In another case, a user preparing to join a clascoterone clinical study after failing with both minoxidil and finasteride also showed interest in the drug's side effect profile. They, like others, noted how side effects from oral finasteride pushed them toward topical solutions like clascoterone. A particularly enthusiastic early post compared clascoterone to “the new Bitcoin” of hair loss products, emphasizing that it may be as effective as finasteride and minoxidil but without the typical side effects. This post, based on early clinical data shared with the community, helped shape expectations that the compound could deliver results with reduced hormonal interference.

    However, not all users find it side-effect-free. One user reported side effects even from clascoterone, grouping it among other anti-androgens like RU58841 and Eucapil that had triggered negative responses. A broader conversation on alternative options for sensitive users included clascoterone among possible solutions, especially for those who experienced systemic effects from finasteride or dutasteride. These posts often described clascoterone as one of the few topicals with clinical backing and relatively mild side effects.

    In summary, the Tressless community’s consensus points toward clascoterone being a promising treatment with a lower side effect burden, especially for people who react poorly to oral anti-androgens. However, it’s not completely free from adverse events. Rare cases of side effects are reported, especially among users sensitive to all anti-androgens, and long-term safety data is still developing.

    In conclusion, clascoterone does have side effects, but they are predominantly mild and restricted to the area of application.

    Skin reactions such as redness, itching, dryness, and burning are the most frequent issues and tend to resolve as treatment continues. Serious systemic effects like hormonal suppression or electrolyte imbalance are exceedingly rare and mostly reversible.Long-term data up to 9 months show consistent safety, and newer research even suggests clascoterone may enhance skin hydration. While not entirely free of risk, clascoterone’s side effect profile is comparatively gentle, particularly when measured against oral acne medications like isotretinoin or spironolactone.

    If you’re considering clascoterone, discuss it with your healthcare provider—especially if you have sensitive skin or are considering treatment for a younger child. And always begin with a patch test before full-face application.

    References

    • Hebert, A., et al. (2020). Efficacy and Safety of Topical Clascoterone Cream, 1%, for Treatment in Patients With Facial Acne: Two Phase 3 Randomized Clinical Trials. JAMA Dermatology. https://www.ncbi.nlm.nih.gov/pubmed/32320027

    • U.S. Food and Drug Administration. (2020). Drug Trial Snapshot: Winlevi. https://www.fda.gov/drugs/drug-approvals-and-databases/drug-trial-snapshot-winlevi

    • Eichenfield, L. F., et al. (2023). Long-term safety and efficacy of twice-daily topical clascoterone cream 1% in patients ≥12 years of age with acne vulgaris. Journal of Drugs in Dermatology, 22(8), 810–816. https://pubmed.ncbi.nlm.nih.gov/37556524/

    • Draelos, Z. D., et al. (2025). Improvement in Skin Moisturization and Lack of Barrier Damage Following Treatment With Clascoterone Cream 1%. Journal of Drugs in Dermatology, 24(4), 397–402. https://pubmed.ncbi.nlm.nih.gov/40196957/

    • Peterson, H., et al. (2023). Clascoterone Cream 1%: Mechanism of Action, Efficacy, and Safety. Journal of Drugs in Dermatology, 22(6), s7–s14. https://pubmed.ncbi.nlm.nih.gov/37276168/

    • DermNet NZ. (2023). Clascoterone: Uses, Side-Effects and More. https://dermnetnz.org/topics/clascoterone

    • Minoxidil....Clascoterone is the new Bitcoin of Hair Loss Products. https://reddit.com/r/tressless/comments/l5kw4c/move_over_finasteride_and_minoxidilclascoterone

    • Tressless Community. (2025, January 14). Joining clinical study for Clascoterone (Breezula). https://reddit.com/r/tressless/comments/1i1g3m9/joining_clinical_study_for_clascoterone_breezula

    • Tressless Community. (2020, September 9). I Get Side-Effects from Anti-Androgens. https://reddit.com/r/tressless/comments/ipizoq/i_get_sideeffects_from_antiandrogens

    • Tressless Community. (2024, May 25). Anyone used CB-03-01 (clascoterone), is it worth it, too risky?? https://reddit.com/r/tressless/comments/1d0n1cc/anyone_used_cb0301_clascoterone_is_it_worth_it

    • Tressless Community. (2024, February 12). Taking part in a Clascoterone Study. https://reddit.com/r/tressless/comments/1ap3i0p/taking_part_in_a_clascoterone_study

    For more user experiences, visit: https://tressless.com/search/clascoterone%20side%20effects