Berberine, a natural alkaloid compound derived from plants such as barberry and goldenseal, has become increasingly popular as a dietary supplement for metabolic health support. Many people taking berberine wonder whether it might cause unwanted side effects, including hair loss. Whilst berberine can produce gastrointestinal symptoms and interact with certain medications, there is currently no established clinical evidence linking berberine supplementation to alopecia. This article examines the available evidence on berberine's side effects, explores factors that may affect hair health during supplementation, and provides guidance on when to seek medical advice for hair loss concerns.

What Is Berberine and How Does It Work?

Berberine is a naturally occurring alkaloid compound extracted from various plants, including Berberis species (barberry), goldenseal, and Chinese goldthread. Traditionally used in Chinese and Ayurvedic medicine for centuries, berberine has gained considerable attention in recent years as a dietary supplement, particularly for metabolic health support.

The compound works through several distinct mechanisms at the cellular level. Berberine activates an enzyme called AMP-activated protein kinase (AMPK), often referred to as the body's "metabolic master switch". This activation influences glucose metabolism, lipid regulation, and cellular energy production. Research suggests berberine may help improve insulin sensitivity, support healthy blood glucose levels, and influence cholesterol metabolism—effects that have made it popular amongst individuals seeking natural approaches to metabolic health.

Berberine also demonstrates antimicrobial properties and may influence gut microbiota composition. It affects various cellular pathways, including those involved in inflammation and oxidative stress. Research studies typically use dosages ranging from 900 to 1,500 mg daily, usually divided into two or three doses to improve absorption and reduce gastrointestinal side effects. However, commercial products vary significantly in strength and quality.

Whilst berberine shows promise in preliminary research, it's important to note that it is classified as a food supplement in the UK rather than a licensed medicine. It is not included in NICE guidance for conditions such as type 2 diabetes. Unlike Traditional Herbal Registration (THR) products, most berberine supplements have not undergone specific regulatory approval. The Medicines and Healthcare products Regulatory Agency (MHRA) does not evaluate supplements with the same scrutiny applied to prescription medications.

Important safety note: Berberine should be avoided during pregnancy, while breastfeeding, and in children due to insufficient safety data.

Potential Side Effects of Berberine

Like any bioactive compound, berberine can produce side effects, though most are generally mild and related to the gastrointestinal system. The most commonly reported adverse effects include:

• Digestive disturbances – diarrhoea, constipation, flatulence, abdominal pain, and cramping

• Nausea – particularly when taken on an empty stomach or at higher doses

• Stomach upset – general gastrointestinal discomfort

These gastrointestinal effects occur because berberine can alter gut microbiota and affect intestinal motility. Taking berberine with meals and starting with lower doses may help minimise these symptoms.

Less common but more significant potential effects include:

• Blood glucose effects – berberine may lower blood glucose levels, which could be problematic for individuals taking diabetes medications (particularly insulin or sulfonylureas). Blood glucose monitoring is advisable if you have diabetes.

• Blood pressure effects – berberine may modestly lower blood pressure. Monitor your blood pressure if you take antihypertensive medications.

• Drug interactions – berberine inhibits certain cytochrome P450 enzymes (particularly CYP3A4 and CYP2D6) and drug transporters (P-glycoprotein), potentially affecting the metabolism of various medications. Particular caution is warranted with medicines that have a narrow therapeutic index, including ciclosporin, tacrolimus, some statins (simvastatin, atorvastatin), certain calcium-channel blockers, and direct oral anticoagulants (DOACs) such as apixaban or rivaroxaban. Consult your pharmacist or GP before combining berberine with prescription medications.

Regarding hair loss specifically, there is no established clinical evidence or official link between berberine supplementation and alopecia (hair loss). Hair loss is not listed amongst the recognised adverse effects in the available scientific literature or supplement safety databases. However, individual responses to supplements can vary, and the lack of comprehensive long-term safety data means that uncommon effects may not yet be fully documented.

Stop taking berberine and seek medical advice if you develop symptoms suggestive of liver problems (such as yellowing of the skin/eyes, dark urine, or severe abdominal pain).

If you suspect berberine has caused any side effects, report them to the MHRA Yellow Card Scheme (yellowcard.mhra.gov.uk).

Factors That May Affect Hair Health While Taking Berberine

If you're taking berberine and experiencing hair loss, it's essential to consider the broader context, as numerous factors can influence hair health independently of supplement use.

Nutritional deficiencies represent a common cause of hair thinning. If berberine causes persistent diarrhoea or digestive upset, this could potentially affect nutrient intake or absorption over time. Iron deficiency, in particular, is a well-established cause of telogen effluvium (diffuse hair shedding). Other nutrients important for hair health include zinc, biotin, and B vitamins. However, you should not start taking additional supplements without discussing with your GP, as over-supplementation carries its own risks.

Metabolic and hormonal changes may also play a role. Berberine influences glucose metabolism and insulin sensitivity, and some preliminary research suggests it may affect hormone levels, though evidence remains limited. Hormonal imbalances—including thyroid dysfunction, polycystic ovary syndrome (PCOS), or changes in androgens—are recognised triggers for hair loss. Whilst berberine is sometimes used to support metabolic health in PCOS, the relationship between berberine, hormones, and hair health requires further investigation.

Underlying health conditions should always be considered. People often take berberine for metabolic concerns such as type 2 diabetes, insulin resistance, or dyslipidaemia. These conditions themselves, along with associated factors like chronic inflammation, oxidative stress, and cardiovascular disease, can independently affect hair growth cycles.

Stress and lifestyle factors cannot be overlooked. Physical or emotional stress, rapid weight loss, inadequate protein intake, and poor sleep all contribute to hair shedding. If you've recently made significant dietary changes alongside starting berberine, these modifications—rather than the supplement itself—might be responsible for any hair changes.

Other common triggers for temporary hair shedding include postpartum changes, recovery from significant illness (including COVID-19), and certain medications. Hair typically regrows once the trigger is removed, though this can take several months.

When to Seek Medical Advice About Hair Loss

You should contact your GP if you experience:

• Sudden or rapid hair loss – particularly if it occurs in patches (alopecia areata) or involves large amounts of shedding

• Hair loss accompanied by other symptoms – such as fatigue, weight changes, skin changes, or menstrual irregularities, which might indicate thyroid dysfunction or other systemic conditions

• Scalp changes – including redness, scaling, pain, itching, or visible inflammation, which could suggest dermatological conditions like seborrhoeic dermatitis or scalp psoriasis

• Hair loss that persists beyond three months – or progressively worsens despite stopping berberine or other supplements

• Concerns about nutritional deficiencies – especially if you've experienced prolonged gastrointestinal symptoms whilst taking berberine

Seek urgent assessment if you experience:

• Scalp pain or tenderness with hair loss

• Signs of scarring or permanent hair loss

• Pustules or severe inflammation of the scalp

• Rapidly progressive patchy hair loss in children (to exclude fungal infection/tinea capitis)

Your GP may recommend investigations including:

• Blood tests – full blood count (to check for anaemia), ferritin (iron stores), thyroid function tests (TSH with free T4 if indicated), vitamin B12, and folate. Zinc levels may be checked if deficiency is clinically suspected.

• Hormonal assessment – particularly if there are signs of hormonal imbalance, such as irregular periods or hirsutism

• Scalp examination – to identify any dermatological conditions requiring specific treatment

According to NICE Clinical Knowledge Summaries, the approach to hair loss depends on the pattern and associated features. Diffuse hair loss (telogen effluvium) often has a reversible cause, whilst patterned hair loss may indicate androgenetic alopecia. Patchy hair loss requires different investigation and may warrant referral to dermatology.

Before your appointment, consider keeping a diary documenting when hair loss began, any supplements or medications you're taking (including berberine dosage), recent life stressors, dietary changes, and associated symptoms. This information helps your GP identify potential triggers and determine appropriate investigations. If you're taking biotin supplements for hair health, inform your GP as these can interfere with certain laboratory tests, particularly thyroid function tests.

If you're taking berberine alongside prescribed medications—particularly for diabetes, hypertension, or other chronic conditions—discuss this with your GP or pharmacist, as interactions could affect treatment efficacy and safety. Never stop prescribed medications without medical advice, even if you suspect they might be contributing to hair loss.

Frequently Asked Questions