Dimethicone: Uses, Side Effects, Dosage - Drugvu

ℹ️ Compiled from public regulatory records · Last regulator revision: May 8, 2026🚩 Report this page

Dimethicone

Other Ectoparasiticides, Incl. Scabicides

Sold as NYDA · Scarzen · Inon Ace · Daily Moisturizing · MediChoice Barrier

US FDACA Health CanadaGB MHRA

Drug class: Other Ectoparasiticides, Incl. Scabicides
Availability: Over-the-counter
Routes: Topical, Oral, Topical (Commercial)
Markets covered: 3
Products on record: 46
FDA reports (12 mo): 1,465

P03AXOther Ectoparasiticides, Incl. Scabicides

Overview

Dimethicone is an active pharmaceutical ingredient in the Other Ectoparasiticides, Incl. Scabicides group (P03AX). The information below is compiled per regulator from the product labels on record, with direct links to the original documents.

Regulatory status by market

Market	Regulator	Products	Last revision
US United States	FDA	32	May 8, 2026
CA Canada	Health Canada	13	April 23, 2026
GB United Kingdom	MHRA	1	October 11, 2024

USUnited States· FDA

32 products

Uses

USOfficial regulatory label· revised January 19, 2024[1]

Uses helps protect from minor skin irritations associated with perineal dermatitis temporarily protects and helps relieve chapped or cracked skin helps protect from the drying effects of wind and cold weather

How to take

CACanada· Health Canada

13 products

Uses

CAOfficial regulatory label· revised March 22, 2025[2]

Dimethicone 100 cSt (NYDA) is indicated for:
Topical treatment of scalp hair in case of infestation with head lice (pediculosis capitis). 1 Pediatrics Clinical studies have been performed in children; therefore, NYDA can be used with children from ages 2 and up. 2 Geriatrics No clinical studies have been performed in elderly patients; however, the use of NYDA should not be of concern.

How to take

GBUnited Kingdom· MHRA

1 product

Uses

GBOfficial regulatory label· revised October 11, 2024[3]

Hedrin is indicated for the eradication of headlice infestations

How to take

GBOfficial regulatory label

Sources & citations

[1]FDA DailyMed · 00e0cd4a-6049-40… · revised January 19, 2024 [PDF]
[2]Health Canada (DPD) · 02373785 · revised March 22, 2025
[3]MHRA (UK) · PL002400345 · revised October 11, 2024
[4]OpenFDA adverse-event reports (US), 12 months ending June 4, 2026.

Information on this page is compiled from public regulatory records. Drugvu is not affiliated with any regulator or pharmaceutical manufacturer. This is not medical advice. Always consult a qualified healthcare professional.

CAOfficial regulatory label· revised March 22, 2025[2]

2 Recommended Dose and dosage Adjustment Appropriate dosage for adult and/or children (2 years or older). NYDA is sprayed carefully over the whole hair. The solution should be massaged in well until the hair is completely wetted with the solution.
The amount of NYDA needed depends on the thickness and length of the hair. The hair near the scalp and behind the ears should be well covered with NYDA, as this is where most lice and nits are found. NYDA should be left on for at least 30 minutes.
Table 1:
Appropriate dosage for adult and /or children (2years or older) Hair Length Average vol. per appl. 4 Administration Before NYDA is used for the first time, the enclosed dispensing pump must be screwed onto the glass bottle. Always hold the spray bottle upright or the pump will not be able to work properly.
Please note that the pump will need to be primed, by pumping, when used for the first time and when it has been unused for a long period. Before treatment with NYDA Inspect all scalp hair of each family member or care giver with the NYDA lice comb.
Treat everyone with lice on the same day to avoid re-infestation. A normal comb or brush can be used before treatment to remove any tangles. This comb should be cleaned thoroughly after use. Cover the shoulders with a towel to protect the clothing.
Administration of NYDA NYDA should be applied to dry hair. 1. The infested hair should be completely covered with NYDA and left for 30 minutes. NYDA is sprayed carefully over the whole hair. The solution should be massaged in well until the hair is completely wetted with the solution.
This can be done using the lice comb, for example. This ensures that all lice, nymphs and nits come into contact with this solution and that the product can work with optimum efficacy. 2. After 30 minutes, the hair may be carefully combed using a lice comb.
After NYDA has been left on for at least 30 minutes, the hair may be combed carefully with the lice comb to remove the suffocated lice and nymphs. NYDA makes combing easier because it contains special ingredients which make even long hair very easy to comb.
3. g. overnight). 4. The hair can then be washed with normal commercial shampoo. 5. After 8 to 10 days, the treatment must be repeated. For complete control of head lice and nits, the treatment must be repeated as described above after 8 to 10 days.
5 Missed Dose In case the second treatment (8 to 10 days after the first treatment) was missed, the hair must be checked for live lice. 4 Administration must be repeated. In case no life lice are found, no further action is required.

Side effects & warnings

CAOfficial regulatory label· Adverse reactions· revised March 22, 2025[2]

1 Adverse Reaction Overview In a clinical study, 145 subjects were treated with either NYDA or with a permethrin-based product. The number of subjects experiencing any adverse events was similar in both groups. , superficial wound after a fall, otitis externa following swimming in a pool).
Two subjects in the NYDA group experienced ocular irritation after treatment when the product entered the eyes. The irritation resolved spontaneously in both cases after washing the eyes with clean water. In a large Postmarketing Surveillance Study in Germany, (833 patients) a total of six adverse events were reported; these included four occurrences of a bothersome hair odour and one occurrence each of a headache and a burning sensation in the eyes.

CAOfficial regulatory label· Warnings and precautions· revised March 22, 2025[2]

General For external use only. Patients should be told that NYDA could react with certain hair care and hair tinting products. Patients should be told to keep away from any open flame or intense heat source which use an open flame and to keep away of any sources of ignition and not to smoke while using this product as the mixture is volatile.
If NYDA is spilled accidentally, there is a danger of slipping. Spillages should therefore be cleaned up immediately. Ear/Nose/Throat Patients should be warned to not use NYDA near the mucosa membranes (nose). Patients should be warned to avoid inhaling NYDA.
Gastrointestinal Patients should be warned to not use NYDA near the mucosa membranes (nose or mouth). Patients should be warned to avoid ingesting NYDA Ophthalmologic Patients should be warned to not use NYDA near the eyes. If product gets into their eyes, patients should immediately rinse for 10-15 minutes with water.
1 Pregnant and Breast-Feeding Women Respiratory Patients should be warned to avoid inhaling NYDA. 1 Pregnant Women No clinical studies have been performed in pregnant women; therefore, NYDA should be used with caution. 2 Breast-Feeding Women No clinical studies have been performed in breast-feeding women; therefore, NYDA should be used with caution.
3 Pediatrics Pediatrics (children less than 2 years of age): No data are available to Health Canada; therefore, Health Canada has not authorized an indication for children under the age of 2. 4 Geriatrics No clinical studies have been performed in elderly patients; however, the use of NYDA should not be of concern.

This is not medical advice. Consult a qualified healthcare professional.

Overview

Regulatory status by market

USUnited States· FDA

CACanada· Health Canada

GBUnited Kingdom· MHRA

Drugs in the same class

Sources & citations