Does HGH cause hair loss? It is a question raised by patients prescribed somatropin for growth hormone deficiency, as well as by those using it outside of medical supervision. Human growth hormone (HGH) plays a vital role in cell regeneration and tissue repair, and its influence on hair follicles — mediated largely through IGF-1 — has attracted scientific interest. However, the relationship between HGH and hair thinning is far more nuanced than many online sources suggest. This article examines the current evidence, explores indirect mechanisms, and outlines when to seek NHS advice.

How Human Growth Hormone Affects Hair Follicles

HGH does not directly damage hair follicles; via IGF-1, it may support follicular growth, and GH excess is more commonly linked to increased hair growth than hair loss.

Not sure if this is normal? Chat with one of our pharmacists →

Human growth hormone (HGH), also known as somatotropin, is a peptide hormone produced naturally by the anterior pituitary gland. It plays a central role in cell regeneration, tissue repair, and metabolic regulation throughout the body. Hair follicles, like many other tissues, contain receptors that respond to growth hormone and its downstream mediator, insulin-like growth factor 1 (IGF-1). This means HGH can, in principle, influence the hair growth cycle.

The hair follicle operates in a cyclical pattern comprising three main phases: anagen (active growth), catagen (transition), and telogen (resting and shedding). Laboratory studies have suggested that IGF-1, which is stimulated by HGH, may support the anagen phase and follicular cell proliferation, though robust clinical evidence in humans remains limited.

Importantly, it is worth noting that conditions of GH excess — such as acromegaly — are more commonly associated with increased hair growth (hypertrichosis) rather than hair loss. This observation supports the view that HGH does not directly damage hair follicles.

When HGH is administered exogenously — either as a prescribed treatment for conditions such as growth hormone deficiency or, illicitly, for performance enhancement — the hormonal environment of the body changes. It has been hypothesised, though not conclusively demonstrated in clinical studies, that these shifts could have downstream effects on other hormones, including androgens such as dihydrotestosterone (DHT), a well-established driver of androgenetic alopecia (pattern hair loss). Any such androgenic pathway would represent an indirect and speculative mechanism rather than a direct toxic effect on follicles.

What the Evidence Says About HGH and Hair Loss

There is no definitive clinical evidence that HGH directly causes hair loss; licensed somatropin SmPCs do not list alopecia as a recognised adverse effect.

Experiencing these side effects? Our pharmacists can help you navigate them →

The direct scientific evidence linking HGH use to hair loss remains limited and largely inconclusive. A review of UK Summary of Product Characteristics (SmPCs) for licensed somatropin preparations — including Genotropin, Norditropin, and Omnitrope, available via the electronic Medicines Compendium (emc) — does not list alopecia or hair loss as a recognised adverse effect. Hair thinning has been reported anecdotally by some individuals using HGH, but this is not consistently reflected in the post-marketing safety data for licensed products.

One theoretical mechanism that has been proposed involves HGH's ability to increase circulating IGF-1 levels, which could hypothetically amplify androgen sensitivity in genetically predisposed individuals. For those with a hereditary tendency towards androgenetic alopecia, this might theoretically accelerate follicular miniaturisation — the process by which follicles progressively shrink and produce finer, shorter hairs. However, this remains speculative and is not supported by robust clinical trial data. It should not be presented as an established pharmacological effect.

It is also worth noting that some individuals who use HGH illicitly may combine it with anabolic steroids, which are strongly associated with hair loss due to their androgenic activity. In such cases, attributing hair thinning solely to HGH is methodologically difficult. Clinical studies on patients receiving somatropin for legitimate medical indications — such as adult growth hormone deficiency — have not consistently demonstrated hair loss as a significant treatment-emergent adverse effect. Overall, there is no definitive clinical evidence that HGH directly causes hair loss, and the association, where reported, is likely indirect and confined to susceptible individuals.

Other Factors That May Contribute to Hair Thinning

Androgenetic alopecia, thyroid dysfunction, nutritional deficiencies, and telogen effluvium are common causes of hair thinning that may be mistakenly attributed to HGH.

When evaluating hair loss in someone using HGH, it is essential to consider the full clinical picture, as many other factors can independently or synergistically contribute to hair thinning. These include:

• Androgenetic alopecia: The most common cause of hair loss in both men and women, driven by genetic sensitivity to DHT. HGH use may theoretically unmask or accelerate this in predisposed individuals, though this has not been confirmed in clinical studies.

• Thyroid dysfunction: Both hypothyroidism and hyperthyroidism are well-recognised causes of diffuse hair loss. Somatropin can influence thyroid hormone metabolism, and thyroid function should be monitored in patients receiving treatment — as recommended in the relevant SmPCs.

• Nutritional deficiencies: Low levels of iron, ferritin, or zinc can impair hair follicle function and lead to telogen effluvium — a form of diffuse shedding triggered by physiological stress. Biotin deficiency is rare in the general population and routine testing is not generally indicated unless there is a specific clinical reason. It is also important to note that the MHRA has issued a Drug Safety Update warning that biotin (vitamin B7) supplementation can interfere with certain immunoassay-based laboratory tests, potentially producing misleading results; patients should inform their clinician of any supplements they are taking before blood tests are arranged.

• Psychological and physical stress: Major illness, surgery, rapid weight loss, or emotional stress can precipitate telogen effluvium, which is often mistakenly attributed to a concurrent medication.

• Scalp conditions: Seborrhoeic dermatitis, alopecia areata, and fungal infections can all cause localised or diffuse hair loss unrelated to HGH.

Individuals using HGH illicitly may not be under medical supervision and may be taking other substances simultaneously. Polypharmacy in this context makes it particularly challenging to isolate the causative agent. A thorough medication and lifestyle history is therefore a critical first step in any clinical assessment of hair loss.

Reporting Side Effects and Seeking NHS Advice

Hair changes during somatropin treatment should be reported via the MHRA Yellow Card scheme and discussed with your prescribing specialist at routine follow-up.

If you are prescribed somatropin through the NHS or a licensed private provider and notice changes in your hair — such as increased shedding, thinning, or changes in texture — it is important to report this through the appropriate channels. In the UK, suspected adverse drug reactions can be reported via the MHRA Yellow Card scheme (yellowcard.mhra.gov.uk). This reporting system helps regulators identify emerging safety signals that may not have been apparent during clinical trials.

Patients receiving somatropin for licensed indications — such as growth hormone deficiency, Turner syndrome, or Prader-Willi syndrome — should have regular follow-up appointments with their specialist endocrinologist. Monitoring typically includes thyroid function and glucose metabolism, as outlined in the SmPCs for licensed somatropin products. Any new or worsening symptoms, including hair changes, should be raised at these reviews. Your specialist can assess whether the symptom is likely treatment-related and advise on whether a dose adjustment or further investigation is warranted.

For individuals who have obtained HGH outside of a medical prescription — for example, for bodybuilding or anti-ageing purposes — it is strongly advisable to seek NHS advice. Using unlicensed HGH carries significant health risks beyond hair loss, including fluid retention, joint pain, carpal tunnel syndrome, and effects on glucose metabolism. The MHRA has also highlighted the risks associated with purchasing medicines from unregulated online sources, where products may be counterfeit or contaminated. The NHS does not endorse the use of HGH for non-medical purposes. Speaking honestly with a GP about any substances being used will allow for safer, more informed clinical care without judgement.

When to Speak to a GP or Specialist

See a GP promptly if hair loss is sudden, patchy, accompanied by systemic symptoms, or causing significant distress; initial investigations include TSH, full blood count, and serum ferritin.

Hair loss can be distressing, and whilst it is not always a sign of a serious underlying condition, certain features warrant prompt medical attention. You should contact your GP if you experience any of the following:

• Sudden or rapid hair loss, particularly if it occurs in patches (which may suggest alopecia areata)

• Diffuse shedding that begins shortly after starting or changing a medication, including somatropin

• Hair loss accompanied by other symptoms such as fatigue, weight changes, cold intolerance, or skin changes, which may indicate thyroid dysfunction

• Scalp inflammation, scaling, soreness, or scarring — particularly if follicular openings appear lost or the scalp feels painful or burning, which may suggest scarring alopecia and warrants prompt dermatology assessment

• Hair loss that is causing significant psychological distress or affecting quality of life

Your GP can arrange initial investigations in line with UK clinical practice. These typically include thyroid function tests (TSH and free T4), a full blood count, and serum ferritin. Androgen testing (such as testosterone and sex hormone-binding globulin) is generally reserved for women presenting with features of hyperandrogenism, such as menstrual irregularity, hirsutism, or virilisation, rather than being performed routinely. Additional tests may be considered if clinically indicated based on history and examination.

Depending on the findings, you may be referred to a dermatologist for specialist assessment of the scalp and hair follicles, or to an endocrinologist if a hormonal cause is suspected. The British Association of Dermatologists and NICE provide guidance on the assessment and management of common hair loss conditions, including androgenetic alopecia, alopecia areata, and telogen effluvium.

If you are currently prescribed somatropin and are concerned about hair changes, do not stop your medication without first speaking to your prescribing specialist. Abruptly discontinuing growth hormone therapy can have broader health consequences. A measured, evidence-based approach — guided by your clinical team — is always the safest course of action.

Frequently Asked Questions