Blis-To-Sol Powder Availability: What Providers and Prescribers Need to Know in 2026

Clinicians treating patients with superficial fungal infections — tinea pedis, tinea cruris, and tinea corporis — may encounter patients who specifically request Blis-To-Sol Powder or who report difficulty finding it at their pharmacy. This guide provides clinical context and practical guidance for managing these situations in 2026.

Overview: Blis-To-Sol Powder and Undecylenic Acid

Blis-To-Sol Powder is an OTC topical antifungal manufactured by Oakhurst Co. Its active ingredient is undecylenic acid with zinc undecylenate. Undecylenic acid is a C11 fatty acid derived from castor oil that was first approved by the FDA as an OTC antifungal decades ago. Despite being one of the oldest OTC antifungal agents, it maintains solid clinical efficacy data.

Mechanism: Undecylenic acid is fungistatic. It disrupts the fatty acid composition of the fungal cell environment, inhibiting the conversion of yeast forms to invasive mycelial (hyphal) forms and inhibiting ergosterol synthesis to a lesser degree than azoles. Zinc undecylenate in the powder formulation adds additional antifungal activity.

Efficacy Data: How Does Undecylenic Acid Compare?

The Cochrane Database of Systematic Reviews conducted a meta-analysis of 72 placebo-controlled trials of OTC topical antifungals for tinea pedis. The reported mycologic/clinical cure rates were:

Undecylenic acid: 72% — highest among OTC options

Allylamines (terbinafine, naftifine, butenafine): 70%

Tolnaftate: 64%

Azoles (miconazole, clotrimazole, ketoconazole): 47%

These data support the use of undecylenic acid as a first-line OTC recommendation. However, it's worth noting that allylamines (particularly terbinafine) are fungicidal rather than fungistatic and may provide faster clinical response. The American Academy of Dermatology recommends topical therapy as first-line for uncomplicated tinea pedis, with oral antifungals reserved for hyperkeratotic, extensive, or refractory disease.

Is There an Official Shortage?

No. Blis-To-Sol Powder is not listed on the FDA Drug Shortage Database as of 2026. Availability issues are distribution-related: Oakhurst Co. has a limited retail distribution network, and the product is not stocked at most major pharmacy chains. Patients can reliably obtain the product through the manufacturer's website (oakhurstco.com), Amazon, and independent pharmacies.

Clinical Guidance: When to Recommend Alternatives

For patients unable to obtain Blis-To-Sol Powder, these alternatives are clinically appropriate for the same indications:

Terbinafine 1% (Lamisil AT): OTC allylamine; fungicidal; first-line for tinea pedis, tinea corporis. Apply once or twice daily for 1-4 weeks depending on the indication. Widely stocked at all major chains.

Tolnaftate 1% (Tinactin): OTC; fungistatic. Available as powder, cream, and spray. Powder form is useful for moisture management in tinea pedis. Also available as daily-use preventive powder.

Clotrimazole 1% (Lotrimin AF): OTC azole; broader spectrum including Candida. May be preferred in cases with possible mixed dermatophyte/yeast etiology.

Ciclopirox (Penlac): Prescription lacquer for onychomycosis; significantly more effective than OTC options for nail involvement.

When to Escalate to Prescription Therapy

OTC antifungals including Blis-To-Sol Powder are appropriate for mild-to-moderate superficial tinea infections. Consider escalating to prescription therapy in the following scenarios:

No improvement after 4 weeks of OTC therapy

Hyperkeratotic or moccasin-type tinea pedis (consider oral terbinafine or itraconazole)

Onychomycosis confirmed by KOH preparation or culture (oral terbinafine preferred; ciclopirox lacquer for mild cases)

Immunocompromised patients with extensive disease

Secondary bacterial superinfection requiring concurrent antimicrobial therapy

How medfinder Supports Your Patients

When patients can't find their medication — even an OTC product — the resulting frustration can lead to non-adherence. medfinder for providers helps your patients locate their prescribed or recommended medications at pharmacies in their area. medfinder calls pharmacies on the patient's behalf and texts them the results — reducing no-fill rates and improving treatment adherence.

See our provider's guide to helping patients find Blis-To-Sol Powder for a step-by-step workflow you can implement in your practice.