Dapsone is a medicine you’ll hear about for a few different problems — leprosy, dermatitis herpetiformis, and sometimes acne. It comes as a pill and as a topical gel. The pill can work well, but it also brings some uncommon yet serious risks. This guide gives quick, useful facts so you know what to watch for and how to stay safer while on dapsone.
Oral dapsone is often given for leprosy and certain blistering or immune-linked skin conditions. Doses for adults usually range from low daily pills up to higher amounts set by your doctor, depending on the condition. Topical dapsone gel (commonly 5%) is used for acne and is applied to the skin once daily. The topical form has much less systemic effect, but side effects can still happen.
If you’re starting dapsone, expect your prescriber to explain why they chose it, how long you’ll need it, and what to watch for. Never adjust doses on your own.
The two big risks are hemolytic anemia and methemoglobinemia. Hemolytic anemia means your red blood cells break down faster than they should. Signs include sudden tiredness, dark urine, pale skin, or yellowing of eyes. Methemoglobinemia reduces the blood’s ability to carry oxygen. Look for bluish lips or fingers, shortness of breath, and unusual fatigue.
People with G6PD deficiency are at much higher risk for hemolysis and should generally avoid oral dapsone. Ask your doctor to check G6PD status before starting.
Other possible issues include headache, nausea, and liver enzyme changes. If you notice jaundice, severe dizziness, or breathing problems, get medical help right away.
Topical dapsone can cause skin dryness, redness, or irritation. It may interact with benzoyl peroxide and cause temporary yellow-orange staining of skin or fabrics; applying them at different times of day reduces this problem.
Some drugs affect dapsone levels or add to its risks. Tell your provider about all medicines you take, especially antibiotics and drugs that can trigger hemolysis or methemoglobinemia.
Before you start, expect baseline blood tests: CBC (complete blood count) and liver tests. Your doctor will repeat blood work after starting — often within the first few weeks — and then at intervals while you continue the drug. These checks catch problems early.
Pregnancy and breastfeeding need a talk with your clinician. Oral dapsone may be used if benefits outweigh risks, but it requires close monitoring. Small amounts pass into breast milk, so decide together with your provider.
Practical tips: always get a G6PD test if your history is unknown, report dark urine or breathlessness fast, use topical dapsone separately from benzoyl peroxide, and keep follow-up blood tests. Ask your pharmacist any questions about interactions or signs to watch for.
Dapsone can be very effective when used correctly. With the right checks and quick reporting of warning signs, you can lower the risks and get the benefit you need. If you’re unsure about anything, call your doctor — they’re the best person to guide your situation.
