Kills Lice

How Hedrin Works

Hedrin’s efficacy is a result of its active ingredients, Dimeticone (Hedrin and Hedrin 15) and Activdiol (Hedrin Treat & Go).

All formulations are patented and have been proven in clinical trials to help kill head lice. As Hedrin works in a purely physical way, Hedrin may work on lice that have developed a resistance to traditional pesticide treatments.


Hedrin ingredients DimeticoneNon-pesticide lotions work in a different way from conventional pesticide treatments. The main active ingredient currently in used in Hedrin is Dimeticone. According to clinical evidence, Dimeticone is the most effective treatment of this nature and in a recent study it was shown to be significantly more effective at treating lice than Malathion*.

Head lice have a unique strategy of water management. Instead of producing urine they eliminate excess water via tiny passages in their exoskeleton called spiracles. When treated with Dimeticone, a silicone oil, it disrupts this process of water management by coating the lice, causing them to become permanently immobile, and blocks their spiracles preventing them from getting rid of excess water.

As a result, any lice that have recently fed could suffer from death by gut rupture and, the ones that haven’t, die of starvation. This physical mode of action means there is theoretically no chance for the lice to build up resistance to the treatment.

How Dimeticone Works

The “carrier” agent for Hedrin is Cyclomethicone which evaporates leaving the active ingredient (Dimeticone) coating the louse. After application the treated hair shows no sign of a treatment being undertaken.

Because Dimeticone kill lice with a ‘physical’ mode of action unlike a traditional chemical pesticide, you can use them as often as you like without the danger of the lice becoming resistant.

Hedrin products are free from solvents that can cause problems in some asthma sufferers.


Hedrin Ingredients ActivdiolLike all insects, head lice are covered by a waxy protective coating. It is this waxy layer that helps the louse maintain its delicate internal water balance, preventing too much water from evaporating.

The Activdiol® in Hedrin Treat & Go works dissolving away this waxy cuticle, limiting its ability to feed and ultimately causing death by dehydration.