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Q: I am getting some hair shedding and I'm on HRT, could it be the HRT?

A: Ordinarily, being on body identical HRT should not cause hair excessive shedding. However it's considering wether HRT has any part in excessive hair shedding.

It is common to shed between 50-100 hairs a day. Individual hair follicles cycle independently, with each hair follicle undergoing 10-30 cycles in lifetime. While most individuals have 100,000 scalp hairs at any time, normal shedding rate occurs at a rate of 50-100 telogen hair per day.

HRT and excessive hair shedding/hair loss

Certain formulations of hormone replacement therapy (HRT) may potentially contribute to hair loss in some individuals, although it's important to note that the effects can vary from person to person. Here are some factors to consider:

1. Progestins: Some progestins, which are synthetic versions of the hormone progesterone, may have androgenic (male hormone-like) effects. These androgenic progestins can potentially exacerbate hair loss or thinning in susceptible individuals. Examples of progestins with higher androgenic activity include levonorgestrel and norethisterone. Body Identical progesterone e.g. Prometrium, is not synthetic therefore should not contribute to hair loss.

2. Testosterone: In some cases, testosterone replacement therapy as part of HRT may lead to hair loss, particularly in women who are sensitive to androgens. Testosterone can be converted into dihydrotestosterone (DHT), a potent androgen that can shrink hair follicles and lead to hair miniaturization, a process associated with male and female pattern hair loss. However, it is worth noting that the target Free Androgen Index range should be in mid range. With your FAI in mid range i.e 2-3 you should ordinarily not expect to experience any hair loss. The Free Androgen Index (FAI) is a test used to assess the amount of biologically active testosterone in the body. It's considered a useful measure because it accounts for both total testosterone levels and the level of sex hormone-binding globulin (SHBG), a protein that binds to testosterone and reduces its availability for use by cells

3. Dosage and Formulation: The dosage and formulation of estrogen and progestin components in HRT can also play a role. Higher doses of estrogen or progestin, as well as certain delivery methods (such as oral pills versus transdermal patches), may have differing effects on hair health. The patch or gel is generally a more favourable way to deliver estrogen. If you are concerned about hair loss, it may be worth discussing switching from tablet estrogen to patch or gel, or a trial of lower dose of estrogen.

4. Individual Sensitivity: Each person's response to HRT is unique. While some individuals may experience hair loss or thinning with certain formulations, others may not be affected at all. Factors such as genetics, hormonal sensitivity, and overall health can influence how a person responds to HRT.

5. Interactions with Other Medications: Some medications, such as certain antidepressants or medications for high blood pressure, may interact with HRT and potentially affect hair health. It's essential to discuss all medications you're taking with your healthcare provider to identify any potential interactions.

For those that like to know Why, What and How.

Let's break down how the dosage, formulation, and delivery method of estrogen and progestin components in hormone replacement therapy (HRT) can impact hair health:

1. Dosage: The amount of estrogen and progestin in HRT can vary depending on the specific formulation and the individual's needs. Higher doses of estrogen or progestin may have more pronounced effects on hormone levels throughout the body, including the hair follicles.

- Estrogen: Estrogen is essential for maintaining hair health, as it promotes hair growth and prolongs the hair growth phase.

- Progestin: Progestin is often included in HRT to protect the uterine lining and balance the effects of estrogen. However, certain synthetic progestins with higher androgenic activity such as levonorgestrel and norethisterone may potentially contribute to hair loss in some individuals, especially at higher doses.

2. Formulation: Different formulations of estrogen and progestin can have varying effects on hair health. For example:

- Type of Estrogen: There are different types of estrogen used in HRT, such as estradiol, estrone, and conjugated estrogens. The specific type and formulation of estrogen can influence its potency and how it interacts with the body's hormonal balance.

- Type of Progestin: Similarly, there are various progestins available for use in HRT, each with its own characteristics and effects. Some progestins have higher androgenic activity than others, which may be a consideration for individuals prone to hair loss.

3. Delivery Method: The method by which HRT is administered can also affect how hormones are absorbed and metabolized in the body, which in turn can impact hair health.

- Oral Pills: Oral HRT pills are absorbed through the digestive system and metabolized by the liver before entering the bloodstream. This route of administration can result in fluctuations in hormone levels, potentially affecting hair health.

- Transdermal Patches: Transdermal patches deliver hormones directly through the skin, bypassing the digestive system and liver metabolism. This can provide more stable hormone levels, which may be preferable for some individuals, especially those sensitive to fluctuations in hormone levels.

By Dr Purity Carr

GP & Menopause Doctor

Harvey, WA 6220

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