Pyrethrum extract and piperonyl butoxide are pediculicides available in over-the-counter (OTC) medicines that kill head lice, body lice, pubic lice (crabs), and their eggs (nits). The two ingredients come together in medicines that kill lice and nits.
The combination of pyrethrum extract and piperonyl butoxide is approved by the U.S. Food and Drug Administration (FDA) and is safe and effective when used according to the Drug Facts label directions. It is very important to apply lice treatments containing pyrethrum extract and piperonyl butoxide to dry hair. Wetting the hair prior to use can dilute the treatment.
- These medicines are for external use only.
- To ensure proper use, read the consumer information enclosed with the product.
- Scalp itching or redness may occur.
- During application, do not use near your eyes. Keep your eyes closed tightly and protect them with a washcloth or towel.
- If any medicine gets into your eyes, immediately flush with large amounts of water.
- If you have lice in the eyebrows or eyelashes, contact a healthcare provider for appropriate treatment.
- Do not use inside the nose, ear, mouth, or vagina.
- Carefully read the instructions for proper louse removal.
- A second treatment must be done in seven to 10 days to kill any newly hatched lice. If infestation continues, consult a healthcare provider.
- You are allergic to ragweed. Breathing difficulty or an asthmatic episode may occur.
- You have difficulty breathing.
- Eye irritation occurs.
- Skin or scalp irritation continues or infection occurs.
- You accidentally swallow the medicine. Immediately contact a healthcare provider or the poison control national helpline at 800.222.1222.