R&C Shampoo®: The Lice Exterminator!

We know lice can be an uncomfortable and embarrassing topic, but it is a very common condition that many people experience at some point in their lives.

Our challenge for you today is to resist scratching your head while reading this article!

Hair lice louse parasite on a single folicle as a close up of the wingless insect living on the hair of human heads as a medical concept of a future danger of infestation of parasitic nits or eggs that will hatch.
Hair lice louse parasite on a single folicle as a close up of the wingless insect living on the hair of human heads.

A Little About Lice

Lice are human parasites that live on the head, body, or pubic area and cause extreme itching1,2. They tend to stay around the root of the hair –  head lice are mainly around the ears and the back of the neck1,2. These blood-sucking insects are visible by the human eye and, about the size of a sesame seed (approximately 2-3 mm3).  Lice can live off the body for around 4 days and lay eggs called nits which hatch after 7 to 10 days1.  Anyone can get head lice but it is more commonly found in children aged 6-113.  Lice can be transferred through hair to hair contact or by sharing objects such as hair brushes, hats, and clothing1,2.  There are many treatment options for this condition, our article focuses on R&C Shampoo®.

What is R&C Shampoo®? How does it work?

R&C Shampoo® is a pediculicide – which means a chemical used to kill lice1,4. The main active ingredients are pyrethrins 0.33% and piperonyl butoxide 4%. Pyrethrins are extracted from the chrysanthemum flower and used to treat head lice and pubic lice (not used for body lice)1. These ingredients are toxic to the lice immune system and work by weakening the breathing muscles, causing their death1.  Piperonyl butoxide is used to enhance the effectiveness of pyrethrins and is also used in many other products to prevent the insects from breaking down the pesticide.

R&C Shampoo® does not kill nits in the hair, so physical nit removal with a nit comb5,6 is required along with the shampoo (see Non-drug Treatments for details).

How Do You Use it1,7?

  1. Apply R & C Shampoo to DRY hair, and massage through hair and scalp
  2. Leave on for 10 minutes
  3. Lather hair with small amounts of water
  4. Rinse well with water
  5. Physically remove nits
  6. Repeat in 7-10 days

Note: Bedmates should also be treated with R&C1.

Safety Concerns: Is This the Right Product for You?

There are very limited side effects reported and it is quite safe relative to other lice treatment products2.  Side effects may include skin rash and skin irritation3,5. Do not use this product if you are allergic to ragweed, chrysanthemum, or petroleum products.  R&C Shampoo® can be used in pregnancy and lactation1. When using the product, avoid contact with the eyes as it can cause eye irritation1.

What Else Should I be Doing to Remove the Lice?

Nit removal should be done after shampooing using a nit comb which you can get from your pharmacy. If the nits are hard to remove, soak hair in vinegar and wrap it in a towel for 30-60 minutes to loosen the eggs from the scalp prior to combing1,8.

Non-drug treatments are essential while using R&C Shampoo® to the prevent spreading of lice6. It is important to wash bed linens and clothes in hot water. You can also store clothes, linens, and stuffed animals in a sealed plastic bag for 2 weeks or in a freezer overnight to kill the lice and nits1. Brushes and combs should be soaked in VERY hot water for 5-10 minutes, you should avoid sharing these items6,7 and any other personal items to avoid the spreading of lice.  Make sure you vacuum anything that cannot be washed.

What Does the Evidence Say?

Many studies have shown that R&C Shampoo® is an effective treatment against lice. R&C Shampoo® does not kill all the unhatched eggs, and does not have lasting residual activity6. The product must be re-applied after 7-10 days from the first time it’s used because it does not kill lice eggs (nits). Even though permethrin 1% (Nix) is the first line treatment for lice, there is an increasing resistance problem making R&C Shampoo® a good alternative6.  It should be noted that there is also an emerging resistance the ingredients in R&C Shampoo®, so other methods can be used if this one is not effective.  These include products such as dimeticones (NYDA®) or Isopropyl Myristate Cyclomethicone (Reslutz®)6.  If these methods fail, you should consult a healthcare professional and talk about other prescription options.

Bottom Line- R&C Shampoo Means No More Mr. Lice Guy!

R&C Shampoo® is effective in treating lice and has minimal side effects. It is safe to use with pregnancy and lactation. Do not use this product if you are allergic to ragweed, chrysanthemum, or petroleum products. The use of R&C Shampoo should be repeated in 7-10 days to ensure the complete elimination of lice.  Non-drug treatments should also be used in along with drug therapy – don’t forget to physically remove the nits with the nit comb!



Kayla Stegmeier, Ke (Shirley) Su, and Mikhail Surgent,  BSc. Pharm Candidate(s)

Faculty of Pharmacy and Pharmaceutical Sciences

University of Alberta

Reviewed by Marian Bae, Bsc. Pharm

Edited and Reviewed by the Health Aisle Team 




  1. Miller, Penny F. (2013). Parasitic Skin Infections: Lice and Scabies. Therapeutic Choices for Minor Ailments: Pg. 688-700.
  2. Parasites – Lice. (2013, September 24). Retrieved April 14, 2015, from http://www.cdc.gov.login.ezproxy.library.ualberta.ca/parasites/lice/
  3. Do-Pham, G., Monsel, G., & Chosidow, O. (2014). Lice. Seminars In Cutaneous Medicine And Surgery, 33(3), 116-118.
  4. Jones, K. N., & English III, J. C. (2003). Review of Common Therapeutic Options in the United States for the Treatment of Pediculosis Capitis. Clinical Infectious Diseases, 36(11), 1355.
  5. HealthWise (2010). Pyrethrins And Piperonyl Butoxide Shampoo – Topical. Retrieved April 10, 2015, from https://myhealth.alberta.ca/health/medications/Pages/conditions.aspx?hwid=fdb5063.
  6. Burkhart, C. G., Burkhart, C. N., & Burkhart, K. M. (1998). An assessment of topical and oral prescription and over-the-counter treatments for head lice. Journal of the American Academy of Dermatology, (6). 979.
  7. The American Society of Health-System Pharmacists (2015). Pyrethrin and Piperonyl Butoxide Topical. Retrieved April 10, 2015 from http://www.nlm.nih.gov/medlineplus/druginfo/meds/a601105.html.
  8. Frankowski, B. L., & Weiner, L. B. (2002). Head Lice. Pediatrics, 110(3), 638
  9. Waldron, P. (2013, November 19). Scour That Scalp: Some Lice Eggs Linger Before Hatching. Retrieved April 11, 2015, from http://news.sciencemag.org/health/2013/11/scour-scalp-some-lice-eggs-linger-hatching