Over-the-counter medication · Topical Antiparasitic
permethrin
Also sold as Elimite, Nix. This medicine treats head lice.
Data updated 2026-05-15
- 1,707
- FDA reportsRarely reported
- $0.23
- Generic price (NADAC)
permethrin (Elimite) is an over-the-counter Topical Antiparasitic. This medicine treats head lice.
Permethrin cream rinse is a medicine that kills lice and their eggs. You put it on your hair to treat head lice.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Generic Price
$0.23/unit
Generic Available
Yes (4 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
This medicine treats head lice.
Common side effects
Itching, Rash, Redness
Key warnings
No specific warnings noted. Always follow your prescriber's instructions.
The sections below are summarized in plain English from permethrin's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Permethrin works by affecting the nervous system of lice. This causes the lice to become paralyzed and die. It also kills the eggs.
How to Take It
First, wash your hair with shampoo (no conditioner). Towel dry your hair so it is damp. Shake the bottle well and put the cream rinse all over your hair and scalp. Leave it on for 10 minutes, then rinse with warm water. If you still see live lice after 7 days, use it again.
This is a plain-language summary of permethrin's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
Pregnancy & Breastfeeding
It is not known if permethrin can harm an unborn baby. Talk to your doctor if you are pregnant or breastfeeding.
This is a plain-language summary of permethrin's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
Missed Dose
This medication is generally only used once, so you don't have to worry about a missed dose. If live lice are seen seven days or more after the first treatment, a second treatment should be given.
This is a plain-language summary of permethrin's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store at room temperature, between 68 to 77°F.
Side Effects (from patient reports)
Based on 1,707 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for permethrin, by number of reports
- Itching
Itching
139 reports
- Pain
Pain
92 reports
- Rash
Rash
78 reports
- Headache
Headache
75 reports
- Feeling sick to your stomach
Feeling sick to your stomach
74 reports
- Dry skin
Dry skin
71 reports
- Hair loss
Hair loss
69 reports
- Feeling worried or nervous
Feeling worried or nervous
69 reports
- Long-term kidney problems
Long-term kidney problems
67 reports
- Diarrhea 54
Diarrhea
54 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for permethrin each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where permethrin sits
permethrin has more FDA adverse-event reports than 11% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is permethrin; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 1,707 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.
Total Reports
1,707
Reports Mentioning Death
59
3.5% of reports — not proof of cause
Hospitalization Reports
228
Top Indication
Lice Infestation
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 2 | PRURITUS | 139 |
| 4 | PAIN | 92 |
| 5 | RASH | 78 |
| 6 | HEADACHE | 75 |
| 7 | NAUSEA | 74 |
| 8 | DRY SKIN | 71 |
| 9 | ALOPECIA | 69 |
| 10 | ANXIETY | 69 |
| 11 | CHRONIC KIDNEY DISEASE | 67 |
| 12 | DIARRHOEA | 54 |
| 13 | FATIGUE | 53 |
| 14 | INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION | 51 |
| 16 | INAPPROPRIATE SCHEDULE OF DRUG ADMINISTRATION | 49 |
| 17 | DYSPNOEA | 48 |
| 18 | EMOTIONAL DISTRESS | 48 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Common Questions
How do I know if I have lice?
How do I apply the cream rinse?
Do I need to comb out the nits?
What if I still see lice after treatment?
Can I use conditioner with this medicine?
How often should I check for lice after treatment?
Can other people in my house get lice?
What should I do with the comb after using it?
Can I use this on my eyebrows or eyelashes?
What do I do if the medicine gets in my eyes?
What are the common side effects of permethrin?
What drug class is permethrin?
Is permethrin safe during pregnancy?
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What the FDA Data Shows for permethrin
The FDA label for permethrin (sold under brand names such as Elimite, Nix) classifies it as an over-the-counter product in the Topical Antiparasitic class. This medicine treats head lice. Official labeling lists 3 commonly reported side effects, including Itching, Rash, Redness.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 1,707 voluntary reports. Interaction data is drawn directly from FDA-approved prescribing information. NADAC pricing from CMS shows a generic unit cost of $0.23.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: November 21, 2022
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages