Spinosad Is a Prescription Topical Treatment Used to Kill Head Lice and Scabies Mites

Spinosad is a prescription topical suspension (0.9%) that treats head lice and scabies by paralyzing and killing the parasites on contact. Sold under the brand name Natroba, it's one of the most effective prescription options available — especially for cases where over-the-counter treatments like Permethrin haven't worked.

If you've been prescribed Spinosad or are trying to learn more about it, this guide covers everything you need to know: what it is, what it treats, how to use it, who shouldn't take it, and what it costs.

What Is Spinosad?

Here are the key facts:

• Generic name: Spinosad topical suspension 0.9%
• Brand name: Natroba
• Drug class: Pediculicide / Scabicide (topical antiparasitic)
• Manufacturer: ParaPRO, LLC
• FDA approvals: Approved for head lice in 2011; approved for scabies in April 2021
• Controlled substance: No — Spinosad is not a controlled substance
• Generic available: Yes

Spinosad is derived from a naturally occurring soil bacterium called Saccharopolyspora spinosa. It's been used in agriculture as a natural insecticide for years and was later developed for human use against lice and mites.

For a deeper dive into how it works at the cellular level, see our article on how Spinosad works.

What Is Spinosad Used For?

Spinosad has two FDA-approved uses:

1. Head Lice (Pediculosis Capitis)

Spinosad is approved for treating head lice in patients 6 months of age and older. It's particularly useful for:

• Lice infestations that haven't responded to over-the-counter Permethrin (Nix)
• Permethrin-resistant head lice (an increasingly common problem)
• Situations where parents want to avoid nit combing — Spinosad kills lice without requiring nit removal

2. Scabies (Sarcoptes Scabiei)

Since April 2021, Spinosad is also approved for treating scabies in patients 4 years of age and older. This was a significant addition because there were very few FDA-approved topical scabies treatments available. It's especially helpful for cases resistant to standard Permethrin 5% cream.

Off-Label Uses

Some doctors use Spinosad off-label for Permethrin-resistant head lice cases and as part of combination therapy for crusted (Norwegian) scabies.

How Is Spinosad Taken?

Spinosad comes as a topical suspension in a 120 mL bottle. It's applied differently depending on the condition being treated:

For Head Lice

1. Shake the bottle well before use
2. Apply to dry scalp and hair, covering the entire area
3. Leave on for 10 minutes
4. Rinse thoroughly with warm water
5. No nit combing is required
6. If live lice are still seen 7 days later, a second treatment may be applied

For Scabies

1. Apply to dry skin from the neck down to the soles of the feet
2. Include between fingers and toes and under fingernails and toenails
3. Let dry for 10 minutes before getting dressed
4. Leave on for at least 6 hours, then wash off in the shower or bath
5. A single application is typically sufficient
6. Multiple bottles may be needed depending on body size

Use up to one full bottle (120 mL) per application for head lice. For scabies, you may need more than one bottle to cover the entire body.

Who Should Not Take Spinosad?

Spinosad is not right for everyone. You should not use it if:

• You are allergic to spinosad or any ingredient in the formulation
• The patient is under 6 months old (for head lice) or under 4 years old (for scabies) — due to the benzyl alcohol content

Additional cautions:

• Pregnant women: No adverse fetal effects were seen in animal studies, but talk to your doctor before using Spinosad during pregnancy
• Breastfeeding women: Spinosad contains benzyl alcohol, which may pass into breast milk with systemic absorption. Discuss with your doctor
• External use only: Spinosad is not for oral, ophthalmic (eye), or intravaginal use

For information about Spinosad side effects, including what's common and what requires medical attention, see our dedicated guide.

How Much Does Spinosad Cost?

Cost is often the biggest barrier for patients who need Spinosad. Here's what you can expect:

• Brand (Natroba): $250 to $400 per 120 mL bottle without insurance
• Generic Spinosad: As low as $121 with a coupon (average retail around $285-$394)
• With insurance: Copay varies. Many plans cover it but may require prior authorization and/or step therapy (trying Permethrin first)

To bring the cost down, check out discount coupons from GoodRx, SingleCare, and RxSaver. For more savings strategies, read our guide on how to save money on Spinosad.

If you're having trouble finding Spinosad at a pharmacy near you, Medfinder can help you locate pharmacies with it in stock.

How Does Spinosad Compare to Alternatives?

There are several other treatments for head lice and scabies. Here's how Spinosad stacks up:

• Permethrin 1% (Nix) — Over-the-counter, first-line for lice. Cheaper but increasingly ineffective due to resistance.
• Permethrin 5% (Elimite) — Prescription cream, first-line for scabies. Effective but some resistance is emerging.
• Ivermectin topical 0.5% (Sklice) — Prescription lice treatment. Similar effectiveness to Spinosad.
• Ivermectin oral (Stromectol) — Used off-label for resistant lice and for scabies. Systemic medication with more potential side effects.
• Malathion 0.5% (Ovide) — Prescription pediculicide. Effective but flammable and has an unpleasant odor.
• Benzyl alcohol 5% (Ulesfia) — Prescription lice treatment that suffocates lice rather than using neurotoxins.

For a full comparison, see our article on alternatives to Spinosad.

Final Thoughts

Spinosad is a powerful, well-tolerated prescription treatment for head lice and scabies. It's especially valuable when over-the-counter options have failed, and the fact that it doesn't require nit combing makes it a favorite among parents and providers alike.

The main drawbacks are cost and availability — but both can be managed. Use coupons to bring the price down, and check Medfinder to find a pharmacy that carries it. If you need help getting a prescription, read our guide on how to find a doctor who prescribes Spinosad.