Last reviewed 2026-05-13 · How we verify

Malathion gel 0.5%

Malathion is an organophosphate insecticide that inhibits acetylcholinesterase, causing accumulation of acetylcholine and paralysis of parasites.

Malathion is an organophosphate insecticide that inhibits acetylcholinesterase, causing accumulation of acetylcholine and paralysis of parasites. Used for Head lice infestation (pediculosis capitis), Scabies (Sarcoptes scabiei infestation).

At a glance

Mechanism of action

Malathion works by irreversibly inhibiting the enzyme acetylcholinesterase in insects and parasites, leading to excessive acetylcholine accumulation at nerve synapses and neuromuscular junctions. This results in overstimulation, paralysis, and death of the target organisms. The gel formulation allows topical application for localized treatment of parasitic infestations.

Approved indications

• Head lice infestation (pediculosis capitis)
• Scabies (Sarcoptes scabiei infestation)

Common side effects

• Scalp irritation
• Pruritus
• Erythema
• Contact dermatitis
• Burning sensation

Key clinical trials

• Efficacy, Safety and Tolerability of a Novel Malathion Formulation in Patients 2 Years and Older With Head Lice (PHASE3)
• Efficacy, Safety and Tolerability of a Novel Malathion Formulation in Patients 2 Years and Older With Head Lice (PHASE3)
• Pharmacokinetics of Malathion Gel 0.5% and Malathion 0.5% Lotion (Ovide) in Patients With Head Lice (PHASE1)

Primary sources

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Competitive intelligence

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• Malathion gel 0.5% CI brief — competitive landscape report
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• Sun Pharmaceutical Industries, Inc. portfolio CI