Cantharidin, a substance derived from blister beetles, has been used by dermatologists for decades to treat common skin conditions like warts and molluscum contagiosum [1.5.2, 1.5.3]. It works as a vesicant, causing a small, controlled blister to form underneath the targeted lesion. This process lifts the unwanted growth off the skin, allowing it to be removed easily as the blister heals [1.5.3]. For many years, physicians relied on compounded versions of this chemical. However, the landscape of cantharidin treatment changed significantly with the introduction of a standardized, FDA-approved product.
The New Standard: FDA-Approval of Ycanth
On July 21, 2023, the U.S. Food and Drug Administration (FDA) approved Ycanth (cantharidin 0.7% topical solution), making it the first-ever FDA-approved treatment for molluscum contagiosum [1.9.1, 1.9.2]. This approval was granted for adult and pediatric patients aged two years and older [1.9.1]. Ycanth is a drug-device combination product that includes a precise, single-use applicator, ensuring a consistent dose is administered by a trained healthcare professional in a clinical setting [1.9.2, 1.9.5]. The approval was based on two Phase 3 trials where 54% of subjects treated with Ycanth achieved complete clearance of all lesions by day 84, compared to just 13% of subjects who received a placebo [1.9.1].
Unpacking the Price Tag: How much does cantharidin cost?
The cost of cantharidin treatment can vary dramatically based on the type of product used (FDA-approved vs. compounded) and the patient's insurance coverage.
The FDA-Approved Option: Ycanth Price
The list price, also known as the Wholesale Acquisition Cost (WAC), for Ycanth is approximately $685 per applicator as of July 2023 [1.3.1, 1.4.2]. Pharmacy discount prices can be found for slightly less, around $660-$677 per applicator [1.3.6, 1.4.5]. It's important to note that this list price does not reflect the final cost to the patient, which is heavily influenced by insurance.
Compounded Cantharidin: A More Affordable Alternative?
Before the approval of Ycanth, dermatologists used cantharidin solutions prepared by compounding pharmacies. These formulations are not FDA-approved, meaning their concentration and purity are not standardized [1.9.2]. However, they are often significantly less expensive. Prices for compounded cantharidin can be as low as $79.95 for a topical solution bottle [1.2.2, 1.4.1]. Other non-standardized products, such as Cantharone, may be found online from Canadian pharmacies for around $110 for a 7.5 ml bottle [1.2.6]. While the upfront cost is lower, these versions are less likely to be covered by insurance.
The Critical Role of Insurance Coverage
Insurance is the single biggest factor determining a patient's out-of-pocket expense.
- Ycanth Coverage: Because Ycanth is FDA-approved, many insurance plans cover it. Verrica Pharmaceuticals, the maker of Ycanth, offers a copay assistance program where eligible, commercially insured patients may pay as little as $25 per treatment visit [1.3.2, 1.4.6]. For patients whose deductible has not been met, the cost may be around $125 per applicator [1.3.3]. Medicare and Medicaid plans generally offer coverage, but cost-sharing details vary by plan and state [1.3.4].
- Compounded Coverage: Insurance plans are far less likely to cover compounded medications, often leaving the patient responsible for the full amount.
The Cantharidin Treatment Process: What to Expect
Treatment with cantharidin must be done in a healthcare provider's office [1.5.4].
- Application: The professional carefully applies the cantharidin solution directly onto each wart or molluscum lesion [1.5.2].
- Drying: The solution is allowed to dry for about five minutes. It should not be covered with a bandage [1.5.4].
- Washing Off: The patient must wash the treated area with soap and water after a specific time, usually 2 to 4 hours, as instructed by the doctor. This is crucial to control the extent of blistering [1.5.1].
- Blistering: A blister typically forms within 24 to 48 hours [1.5.5]. This can be accompanied by itching or mild discomfort [1.5.3].
- Healing: Over the next week, the blister dries, a scab forms, and the lesion falls off, leaving new skin underneath. The entire process to clear the lesion usually takes one to two weeks [1.5.1, 1.5.5]. Multiple treatments, spaced about three weeks apart, may be necessary [1.9.1].
Safety, Side Effects, and Important Precautions
Cantharidin is effective but potent, and strict safety measures are essential.
Key Safety Warnings:
- For Professional Use Only: It must only be applied by a healthcare provider [1.9.1].
- Life-Threatening if Swallowed: Oral ingestion can cause kidney failure, blood clotting issues, seizures, and can be fatal [1.8.2, 1.8.5].
- Severe Eye Damage: Accidental contact with the eyes can lead to severe irritation, scarring, and even blindness. Eyes should be flushed with water for at least 15 minutes and emergency medical attention sought if contact occurs [1.8.2, 1.8.3].
- Flammable: The solution is flammable, even after it has dried on the skin. Patients must avoid fire, flames, or smoking until the medication is washed off [1.5.4, 1.8.5].
Common side effects are typically localized to the application site and include blistering, pain, itching, scabbing, redness, and changes in skin color [1.8.3].
Comparing Treatment Alternatives
Cantharidin is one of several options for treating warts and molluscum. Patients should discuss the best approach for their situation with a dermatologist.
| Treatment | Typical Cost (Without Insurance) | Mechanism of Action | Pros | Cons |
|---|---|---|---|---|
| Ycanth (Cantharidin) | $685+ per applicator [1.3.1] | Chemical vesicant (blistering) | FDA-approved, high efficacy, painless application [1.9.1, 1.5.2] | High list price, requires office visit, potential for painful blisters [1.3.1, 1.5.1] |
| Compounded Cantharidin | $80 - $200 per session [1.2.2, 1.6.1] | Chemical vesicant (blistering) | Lower upfront cost, painless application [1.4.1, 1.5.2] | Not FDA-approved, inconsistent potency, unlikely to be insured [1.9.2] |
| Cryotherapy | Varies (in-office procedure) | Freezes lesion with liquid nitrogen | Widely available, effective | Can be painful, risk of scarring or discoloration [1.5.3] |
| Salicylic Acid | $20 - $55+ (OTC) [1.6.2] | Gradually dissolves keratin protein | Inexpensive, available over-the-counter | Requires daily application for weeks, can irritate skin [1.6.6] |
| Imiquimod | $135 - $1,100+ (prescription) [1.6.1] | Immune response modifier | Can be applied at home, effective for some | Expensive, can cause significant skin inflammation, takes weeks to work [1.6.2] |
Conclusion: Making an Informed Decision
When considering treatment for molluscum or warts, understanding how much cantharidin costs requires looking beyond the sticker price. The introduction of the FDA-approved Ycanth provides a standardized, effective, and often insurable option, though its list price is high [1.3.1, 1.9.1]. Copay programs can make it highly affordable for those with commercial insurance [1.3.2]. Cheaper compounded versions remain an option, but they come without FDA oversight and are typically paid for out-of-pocket [1.2.2, 1.9.2]. Ultimately, a consultation with a dermatologist is the essential first step to weigh the costs, benefits, and risks of all available treatments to find the most appropriate and cost-effective path forward.
For more information on the FDA's approval and safety guidelines, you can visit the FDA's official announcement on Ycanth [1.9.1].
