About Hair Testing

Hair cortisol testing is an exciting developing area of research and our speciality.  Collection of hair samples is minimally invasive, safe, quick, pain-free, and can be performed with minimal training.

Hair as a medium differs significantly from blood, saliva and urine as it allows a researcher to look at cortisol integration over a much longer timescale, from 1 month in the past up to 6 months in the past at the time of sampling. This allows researchers to look at chronic stress, general stress levels, long-term treatment/response and also to test retrospectively from samples taken after a stressful event or period. 

Initial studies have been carried out on non-scalp hair and measuring other hormones such as testosterone. Contact us for details.


Hair Sample Collection- Confounding issues and technical resources

Sampling for hair cortisol extraction is simple in principle, but can be tricky to get right. In this section we provide a guide to sampling that aims to give the best possible results. See collecting hair samples and samples and segments. 

Fewer considerations are necessary when taking samples for hair cortisol than when sampling for salivary measures, but there are still several potential confounders of hair cortisol results that should be considered when designing your questionnaires and screening your participants for study.  These include hair treatments, groups with little hair e.g. babies and firefighers, ethnic differences and methodological difference. Many of these are covered in the technical references below:

  • The original paper that inspired the recent trend for humans hair testing: 
  • Some useful papers that show potential confounders of hair cortisol measures: http://www.ncbi.nlm.nih.gov/pubmed/17892760 http://www.ncbi.nlm.nih.gov/pubmed/22356099
  • A comparison of ELISA kits and methods for hair cortisol extraction: 
  • Some comparisons of hair cortisol to salivary and/or urinary cortisol measures: http://www.ncbi.nlm.nih.gov/pubmed/21397617 http://www.ncbi.nlm.nih.gov/pubmed/27235635