How often should I wash my hair with lice shampoo? - briefly
Apply the lice shampoo once, then repeat after 7‑10 days to eliminate any newly hatched lice; additional washes are unnecessary unless reinfestation is confirmed.
How often should I wash my hair with lice shampoo? - in detail
The recommended interval for using a lice‑treatment shampoo is determined by the parasite’s life cycle and the product’s instructions. Initial application eliminates active insects; a second application targets newly hatched nymphs that survived the first treatment.
Manufacturers typically advise a single wash, followed by a repeat after 7–10 days. The instruction often reads «repeat after 7–10 days». This timing aligns with the average 9‑day incubation period from egg to mature louse.
A practical schedule may include:
- First wash – apply shampoo according to label, leave on for the specified duration, then rinse thoroughly.
- Wait 7–10 days – maintain regular hair hygiene but avoid re‑application.
- Second wash – repeat the same procedure to eradicate any newly emerged insects.
- Optional third wash – if live lice are still observed after the second treatment, a third application 7 days later may be warranted.
Additional measures support the chemical treatment:
- Use a fine‑toothed lice comb on wet hair after each wash to remove nits.
- Wash bedding, hats, and personal items in hot water (≥60 °C) or seal them in plastic bags for two weeks.
- Vacuum carpets and upholstery to reduce environmental reservoirs.
In cases of resistant lice strains or severe infestations, a healthcare professional may prescribe a more aggressive regimen, but intervals shorter than three days are generally discouraged to avoid scalp irritation and reduced efficacy.
Following the outlined timing—initial wash, a 7–10‑day interval, and a second wash—provides comprehensive coverage of the lice life cycle while minimizing unnecessary chemical exposure.