Can Antibiotics Cause Hair Loss? Here’s What Science Says

Reading time: 8 min.

Medically reviewed by
Dr Harpreet Kalra (GMC) — Updated on December 29, 2025

While antibiotic consumption in the UK has declined by 15% since 2017 [1], these safe and effective medications still save lives every day, as they are frequently used to treat a wide array of conditions. Antibiotics are generally well-tolerated by patients but, like every drug, they can sometimes have adverse reactions, including gastrointestinal issues, fever, aches and pains, sensitivity to light, allergic reactions, and liver and heart problems [2]. But can antibiotics cause hair loss?

Despite occasional reports, at this time, there is not enough scientific evidence to suggest that taking antibiotics can make your hair fall out. On the contrary, this class of medications is sometimes used to treat hair follicle infections that can cause hair loss. However, there may be some indirect links between antibiotic use and hair thinning. This article will tell you:

How antibiotics work to treat infections
The relationship between antibiotics and hair loss
Other medications that can cause hair thinning
What to do if you are experiencing hair loss while taking antibiotics

Table of Contents

How do antibiotics work?
Can antibiotics cause hair loss?
How might antibiotics cause hair loss?
Is antibiotic hair loss reversible?
Can antibiotics help hair loss?
What other medications can cause hair loss?
What to do if your hair is falling out while taking antibiotics
Frequently asked questions

How do antibiotics work?

Antibiotics are a class of medications that can treat or prevent bacterial infections. Some antibiotics destroy bacteria by damaging their cell walls or interiors. Others prevent these microorganisms from multiplying, so the infection doesn’t spread and your immune system can overcome them more easily [3].

Antibiotics are extremely useful in treating a variety of conditions, from mild strep throat to bacterial meningitis [3][5]. However, these drugs cannot always discern between harmful and helpful bacteria in your body. So they may also inadvertently destroy some of the good bacteria that help with processes such as digestion or disease protection [5]. This can lead to imbalances in your microbiome (the collection of microbes that live naturally within your body) [6].

Take any antibiotics exactly as prescribed by your doctor. Taking them unnecessarily (e.g. self-medicating for viral infections) or stopping treatment too early can lead to bacteria building resistance to these medications. This is a significant problem worldwide, considered one of the top 10 threats to global health by the World Health Organization [7]. That is because it can significantly decrease antibiotic treatment effectiveness, as increasingly resistant bacteria stop responding to it [8].

Can antibiotics cause hair loss?

There is anecdotal evidence that antibiotics can cause hair loss, but so far, no scientific studies have confirmed this. Very little research has been conducted regarding the effect this type of medication can have on hair growth and it has yielded more questions than answers. That is because the link between our bacterial microbiome and our hair follicles is just beginning to be studied [9][10].

There have been a few reported cases of a certain antibiotic being associated with the onset of alopecia areata (e.g. rifampicin) [11] or with telogen effluvium (e.g. azithromycin) [12]. However, it is difficult to attribute the hair loss to these medications, as they could have been triggered by a variety of factors. For example, simply having an infection (e.g. COVID-19) accompanied by fever can sometimes be enough for telogen effluvium to set in [12].

Moreover, antibiotics have undergone decades of clinical trials and their side effects are largely known. There is no mention of hair loss in the literature describing their adverse reactions [2][3][13][14]. Nor are antibiotics mentioned in articles researching medications that cause hair loss [15][16][17]. This doesn’t mean that they cannot cause hair thinning, but more evidence is needed to determine the likelihood and circumstances of this event. And any antibiotic-induced hair loss would likely be mild to moderate, as severe cases are usually noticed and recorded in medical literature.

How might antibiotics cause hair loss?

Based on the clues science provides at this time, were antibiotics to cause hair shedding, it would likely be indirectly, through one of the following mechanisms.

Depleting your nutrient reserves

Some types of antibiotics (such as gentamicin and tetracycline) can affect the levels of certain essential nutrients in your body. They can do so either by causing them to be excreted in larger quantities than normal or by binding to them, preventing absorption.

It is a known fact that some mineral and vitamin deficiencies cause hair loss. This is the case of clinical vitamin B12, iron, magnesium or zinc deficiencies [18]. However, you’re unlikely to develop a deficiency as a result of taking antibiotics unless you take a prolonged course, and/or already have an inadequacy or a preexisting condition that prevents proper nutrient absorption.

If you are taking long courses of antibiotics, it is a good idea to monitor your nutrient levels and supplement as needed. That is because after the alopecia sets in, supplementation can treat it in many cases, but it is not guaranteed to work every time. Speak to your GP about supplements if you’re worried.

Altering the microbiome around your hair follicles

The role your microbiome plays in fostering hair growth and preventing hair loss is only beginning to be studied. Some preliminary research indicates that some antibiotics may have positive effects on hair production and help regulate the hair growth cycle. They do so by promoting the proliferation of helpful bacteria while inhibiting harmful ones [9]. However, others may have a negative effect, by causing imbalances in your scalp microbiome.

Some researchers noted that patients with alopecia areata have certain imbalances in their scalp microbiome, which may play a role in the onset or worsening of this disorder [19]. While clinical trials are needed to prove this, certain antibiotics may cause such imbalances, potentially leading to patchy hair loss.

Significantly more research is needed to identify the relationship between the scalp biome and hair loss. This may help to clarify the role of antibiotics in hair loss.

Is antibiotic hair loss reversible?

If your hair loss is caused by an antibiotic treatment, it is likely reversible. In most cases, it should resolve itself without any treatment within 3-4 months of finishing your medication course. If 6 months have elapsed since you stopped treatment and you are still experiencing excessive hair shedding, it is best to see a trichologist. They can help you rule out other types of alopecia (such as androgenetic alopecia).

Can antibiotics help hair loss?

Yes, antibiotics are sometimes used to treat certain scalp infections that can cause hair loss, such as severe forms of scalp acne (e.g. acne necrotica) or scalp folliculitis [20]. They can also be used to treat some forms of inflammatory scarring alopecia that are not caused by infection but can be worsened by the presence of bacteria (e.g. folliculitis decalvans) [21].

Moreover, topical antibiotics are often used preventively on the scalp right before and during the first few days after a hair transplant surgery. They reduce the chances of developing a hair transplant infection, which could diminish graft survival rates and ruin the result.

What other medications can cause hair loss?

Most people know that chemotherapy can cause hair loss. However, other types of drugs can also lead to excessive hair shedding. Here are some of the most common [15][16]:

Certain types of psychiatric medication (e.g. lithium)
Some heart medications (e.g. captopril)
Some thyroid medications (e.g. antithyroid medication for hyperthyroidism)
Some blood thinners (e.g. warfarin)
Some oral contraceptives (e.g. certain progesterone-based formulations)
Some cholesterol medications (e.g. clofibrate)

Furthermore, even taking too many vitamin supplements may harm your hair, as excessive vitamin A can also cause hair loss. That is why it is always a good idea to get a doctor’s recommendation and learn about potential side effects before taking any medication or nutritional supplement.

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What to do if your hair is falling out while taking antibiotics

If you are currently taking antibiotics and you have noticed more hair shedding than usual, don’t stop taking your medication early, even if you feel better. That can cause your infection to return and can contribute to increasing bacterial resistance. The best thing you can do is to book a consultation with one of our experienced trichologists. They will run diagnostic tests (including hair loss blood tests if needed) to determine whether your alopecia is antibiotic-induced or if you are seeing the first signs of hair thinning and balding from an unrelated condition.

If your hair loss is caused by antibiotics, it will improve on its own when you stop taking the medication. If the treatment is long-term, the hair doctor may recommend Minoxidil to help nourish your hair and stimulate your hair follicles for growth.

However, if it is caused by a different condition, they will recommend the best hair loss treatment for women with your specific problem, or a male hair loss treatment depending on your needs. And they will be there for you every step of the way to help you get fuller, healthier hair.

Frequently asked questions

If you are curious to find out more about the link between antibiotics and hair loss, don’t miss out on the answers to these frequently asked questions.

How long does hair loss from antibiotics last?

It is uncommon for antibiotics to cause hair loss, but should they do so, it would likely be due to telogen effluvium. The diffuse hair loss caused by this condition usually takes 3-4 months to resolve after the end of the event that triggered it (in this case, treatment cessation or the rebalancing of nutrients in the case of antibiotic-induced nutrient deficiency).

On rare occasions, telogen effluvium can become chronic and last for years. That is why it is a good idea to see a trichologist for any hair loss that exceeds 5-6 months.

Is there a way to prevent antibiotics-induced hair loss?

Unfortunately, there is no way to prevent antibiotic side effects. It’s really important to take the medicine as prescribed and complete the full course, even if you’re concerned about hair loss.

However, you can be sure you are getting enough nutrients by eating a healthy diet for hair. If you have a condition that predisposes you to nutritional deficiencies, you may also want to monitor the respective nutrient levels and supplement accordingly during your treatment course.

Do certain antibiotics cause more hair loss than others?

At this time, no studies have been conducted to compare the effect of different antibiotics on hair loss. Longer treatment courses have an increased likelihood of developing unwanted side effects, but more research is needed to determine if they are also more likely to make your hair fall out than shorter ones.

Antibiotics make my hair fall out - should I ask for a different treatment?

If you have a history of excessive hair shedding associated with antibiotic treatments, you can mention this to your doctor. For certain conditions, they may be able to provide treatment alternatives. But keep in mind that in most cases, antibiotic hair loss is rare and temporary. However, bacterial infections can progress and have a serious impact on your health if not properly treated. Severe infections can also trigger telogen effluvium.