Natroba™ safety starts with a naturally occurring active ingredient.
Unlike the synthetic permethrin found in OTC treatments6, the active ingredient in Natroba™ is spinosad—derived from a naturally occurring soil microorganism.1

Mechanism of Action
Along with a highly sensitive and selective mechanism of action that differs from neurotoxic agents like permethrin and pyrethroids:
The active ingredient, spinosad, targets lice and nits right where they live–doesn’t go beyond the stratum corneum, before breaking down through desquamation;4
Spinosad, the active ingredient, breaks down through the natural desquamation process, with no systemic absorption even in patients as young as six (6) months of age;2,4
No evidence of neurotoxicity, developmental/reproductive toxicity, immunotoxicity, mutagenicity, or carcinogenicity from spinosad exposure.5
What the clinical trials revealed
Natroba™ demonstrated similar or lower treatment related AEs versus the leading OTC medication, Nix® (permethrin 1%).3
No systemic absorption
Spinosad, the active ingredient, was below the level of quantitation (3ng/mL), even in patients as young as six (6) months of age.4
No lab abnormalities
No clinically significant laboratory test results were reported for spinosad. A review of the individual and summary laboratory test results did not identify any safety signal.5
No toxicities
No evidence of neurotoxicity, developmental/reproductive toxicity, immunotoxicity, mutagenicity, or carcinogenicity from spinosad exposure.5
No environmental effects
EPA concludes reasonable certainty that no harm will result to the general population, or to infants and children from aggregate exposure to spinosad residues.5
Nix® is a registered trademark of Prestige Brands, Inc.
References:
- Millar, N. S. & Denholm, I. Nicotinic acetylcholine receptors: targets for commercially important insecticides. Invert. Neurosci. 7, 53-66.
- Natroba Prescribing Information.
- Stough D, Shellabarger S, Quiring J, Gabrielsen A. Efficacy and safety of spinosad and permethrin crème rinses for pediculosis capitis (head lice). Pediatrics. 2009;124(3): e389-395.
- Data on file.
- Federal Register /Vol. 80, No. 248 /Monday, December 28, 2015 /Rules and Regulations.
- CDC-Headlice-Treatment-OTC Medications (8.18.2016). Retrieved from https://www.cdc.gov/parasites/lice/head/treatment.html
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