How long should you leave shampoo on hair for lice? - briefly
«Leave the lice‑treatment shampoo on the hair for approximately ten minutes before rinsing.»
«After rinsing, comb the hair with a fine‑tooth lice comb to remove any remaining nits.»
How long should you leave shampoo on hair for lice? - in detail
The active ingredient in lice‑removing shampoo must remain on the scalp long enough to penetrate the exoskeleton of the parasite and disrupt its nervous system. Most formulations containing permethrin or pyrethrin specify a minimum contact time of 10 minutes. Some dimethicone‑based products recommend 5 minutes, followed by a thorough rinse. Extending the exposure beyond the minimum does not increase efficacy and may raise the risk of scalp irritation.
Procedure:
- Apply the shampoo to dry hair, ensuring complete coverage from roots to tips.
- Massage gently to distribute the product, avoiding vigorous scrubbing that could cause abrasion.
- Leave the solution on the scalp for the period indicated on the label (generally 5–10 minutes).
- Rinse thoroughly with lukewarm water, removing all residue.
- After drying, use a fine‑tooth lice comb to remove dead insects and nits.
- Repeat the treatment after 7–10 days to eliminate any newly hatched lice that survived the first application.
Safety considerations:
- Keep the product away from eyes; flush immediately with water if contact occurs.
- Do not apply to broken or inflamed skin.
- For children under two years old, verify that the specific shampoo is approved for that age group.
Adhering strictly to the recommended contact time and following the post‑treatment combing protocol provides the highest likelihood of eradicating an infestation.