Head lice are a major hassle, as you well know if you or a child you care for has ever been infested. Along with the ick factor, social stigma and awful itching, there’s the painstaking task of nit-picking—removing every single egg, or nit, from every strand of hair. It’s quite a chore because the special shampoos that kill the lice typically leave behind the nits, which are virtually cemented onto the hair shafts…and some of which can go on to hatch and start the cycle of infestation all over again.

Some people go so far as to hire professional nit-pickers to search hair-by-hair and remove each egg by hand. Others try various home remedies…while still other turn to special commercial hair products to do the job. But what really works best? A new study has the answer—and it’s sure to surprise you…

HAIRY INVESTIGATION

For the new study, more than 600 individual hairs, each with a single nit, were cut from the scalps of patients with pediculosis (lice infestation). The researchers then tried different treatments on the hairs to determine which made it easiest to remove the stuck-on nits. They quantified the effort needed to remove nits by using an instrument called a force transducer and other devices that measure force.

What they discovered: Not surprisingly, removing nits from hair that was completely untreated required the most force. Soaking the hair in water for 10 minutes significantly reduced the force required, though it still didn’t make the job easy. What was surprising…

Almond oil, a popular home remedy, did not help at all when it was applied and then rinsed off—the force required in this case was even greater than that required for untreated hair. When almond oil was applied and left in the hair, the force required to remove the nits was comparable to the force required with just water. But as the researchers pointed out, almond oil itself can be nearly as difficult to remove as nits…which means that this home remedy is no winner.

Commercial chemical-based nit-removal products worked no better than water when applied and then rinsed off according to manufacturers’ instructions. “Active ingredients” such as formic acid or acetic acid did not help at all.

What worked best at loosening stubborn nits was to wet the hair and then apply ordinary hair conditioner and leave it in—not rinse it out—before attempting to remove the nits. Commercial nit-removal products that were applied and left in (contrary to manufacturer instructions) worked about as well as—but no better than—ordinary hair conditioner.

Explanation: Hair conditioner coats hair with fatty alcohols and sometimes with silicones, lubricating the hair very effectively and making it much easier to dislodge the nits with a comb—especially when the conditioner is not rinsed out.

What to do: First kill already-hatched lice with a commercial product designed to do this. Next, wet the hair completely and apply hair conditioner (don’t rinse!). Then, working with one small section of hair at a time, comb each section very thoroughly from the roots all the way down to the ends of the strands to dislodge the nits. A good comb to use is the LiceMeister comb. which has tines specially designed for this purpose. Developed by the National Pediculosis Association, it sells online and in some drugstores for about $12.