Blis-To-Sol Powder Side Effects: What to Expect and When to Call Your Doctor

Blis-To-Sol Powder is generally well-tolerated. Because it's applied topically — directly to the skin — very little is absorbed into the bloodstream, which means systemic side effects are rare. That said, like all medications, it can cause skin reactions in some people. Here's what you should know.

Common Side Effects of Blis-To-Sol Powder

The most frequently reported side effects with Blis-To-Sol Powder are mild and typically involve the skin at the application site:

Mild skin irritation — Some temporary redness or sensitivity at the application area

Itching — A mild itch at the treatment site is common, especially early in treatment

Dryness — The powder formulation can dry the treated area; this is often part of how it works

Peeling — Light peeling of the treated skin is normal and may indicate the infection is resolving

Burning sensation — A mild, temporary burning upon application can occur, especially if the skin is already raw or inflamed

These effects are usually mild and get better as your skin adjusts to the medication. They do not typically require stopping treatment.

Serious Side Effects: Stop Using and Call Your Doctor

Stop using Blis-To-Sol Powder immediately and seek medical attention if you experience any of the following:

Signs of an allergic reaction: Hives, difficulty breathing, or swelling of the face, lips, tongue, or throat. Call 911 or go to the emergency room immediately.

Severe skin irritation that was not present before using the medication: If the treated area becomes significantly worse — with increased redness, swelling, blistering, or pain — stop using the product and call your doctor.

No improvement after 4 weeks: If your infection hasn't improved after 4 weeks of twice-daily use, stop and consult your healthcare provider. You may have a different condition, a resistant organism, or need prescription-strength treatment.

Is Blis-To-Sol Powder Safe to Use on All Skin Types?

Blis-To-Sol Powder is generally safe for most adults and children over 2 years old. However, certain conditions require extra caution:

Sensitive skin: Ask a pharmacist before use if you have very sensitive skin or a history of skin reactions.

Open wounds or broken skin: Do not apply to open wounds, blisters, or actively broken skin. Wait until the skin has at least partially healed before applying.

Pregnancy: It is not known whether Blis-To-Sol Powder harms an unborn baby. Consult your doctor before using during pregnancy.

Breastfeeding: It is not known whether undecylenic acid passes into breast milk. Consult your doctor before use while breastfeeding.

Children under 2: Do not use on children under 2 years of age without a doctor's guidance.

Does Blis-To-Sol Powder Have Any Drug Interactions?

Because Blis-To-Sol Powder is applied topically with minimal systemic absorption, it has very few known drug interactions. Medications you take by mouth or by injection are unlikely to be affected by topically applied undecylenic acid.

The main caution: avoid using multiple topical antifungals on the same area at the same time unless directed by your doctor. Using two products together doesn't necessarily improve results and may cause more skin irritation.

How to Use Blis-To-Sol Powder Safely

To minimize side effects and maximize effectiveness:

Wash and thoroughly dry the affected area before applying

Apply twice daily to affected area and surrounding skin

Don't bandage the treated area (use a light cotton gauze only if needed)

Continue treatment for 2 weeks after symptoms disappear to prevent recurrence

Keep the product out of reach of children and away from eyes, nose, and mouth

When to Seek Emergency Care

Call 911 or go to the emergency room if you experience signs of a severe allergic reaction after applying Blis-To-Sol Powder: hives, difficulty breathing, rapid heartbeat, or swelling of the face or throat. These reactions are rare but serious.

For more on drug interactions with topical antifungals, see our guide on Blis-To-Sol Powder drug interactions.