What Antibiotics Cause Hair Loss?
Some antibiotics are linked to temporary hair shedding, most often because illness and medication stress can push more hairs into the resting (telogen) phase. This is called telogen effluvium and usually improves after treatment ends. Certain classes—like tetracyclines, sulfonamides, penicillins, and fluoroquinolones—are reported more often than others.
Can Antibiotics Really Cause Hair Loss?
Hair loss isn’t a common antibiotic side effect, but some people notice extra shedding during or after treatment. In many cases, the bigger trigger is the infection itself—fever, inflammation, poor sleep, and reduced appetite can all disrupt the hair cycle. When shedding starts, it often appears weeks to a few months after the trigger rather than immediately.
How Antibiotics May Trigger Shedding
Telogen effluvium from physical stress
Telogen effluvium is temporary, diffuse shedding caused by a shift in the hair growth cycle. A significant stressor—like a bacterial infection, high fever, surgery, or a new medication—can push more hairs into the resting phase. Those hairs then shed later, which is why people often link the shedding to a medication they took weeks earlier.
Changes in gut bacteria and nutrient absorption
Some antibiotics can temporarily disrupt gut bacteria. If your digestion is off or your appetite drops, you may fall short on nutrients that support normal hair growth, such as iron, zinc, B vitamins, and protein. This doesn’t happen to everyone, but it can make shedding more noticeable in people who already have low stores.
Rare drug reactions that affect the scalp
Less commonly, a person may develop a medication reaction that includes rash, inflammation, or systemic symptoms. When the body is dealing with widespread inflammation, hair shedding can increase. If you notice hives, swelling, blistering, fever, or facial swelling, seek medical advice urgently.
Antibiotics Most Often Linked to Hair Shedding
Research on antibiotic-related hair loss is limited, and shedding is usually uncommon. Still, the following classes are reported more often in patient reports and side-effect lists. If you’re taking one of these, it doesn’t mean you will lose hair—only that it’s worth watching for changes.
Tetracyclines (doxycycline, minocycline)
Tetracyclines are widely used for acne and some infections. When shedding happens, it’s often linked to telogen effluvium, appetite changes, or digestive upset that affects nutrition. If you’re on a longer course, make sure your diet is steady and talk to a clinician if shedding becomes significant.
Penicillins (amoxicillin, ampicillin)
Penicillin antibiotics are commonly prescribed and are generally well tolerated. Hair shedding is not typical, but some people report thinning during recovery from the infection they were treating. If shedding starts after a severe illness, telogen effluvium is often the more likely explanation.
Sulfonamides (trimethoprim-sulfamethoxazole)
Trimethoprim-sulfamethoxazole (often known by brand names such as Bactrim) lists hair loss among possible side effects for some patients. Shedding may be more noticeable if the medication causes reduced appetite, stomach upset, or if you were already low in iron or zinc. Report new or severe side effects to your prescriber, especially if you also develop a rash.
Fluoroquinolones (ciprofloxacin, levofloxacin, moxifloxacin)
Fluoroquinolones are used for certain infections when they’re clinically appropriate. Hair shedding has been reported, though it appears uncommon and can be difficult to separate from the stress of infection. If you experience multiple new symptoms—such as tendon pain, nerve symptoms, mood changes, or significant hair shedding—contact your clinician promptly.
Who Is More Likely to Notice Hair Loss During Antibiotic Use?
Extra shedding is more likely when several factors overlap. Common risk factors include:
- A recent high fever, severe infection, or hospitalization
- Prolonged or repeated antibiotic courses
- Low iron, vitamin D, zinc, or B12 levels
- Rapid weight loss, low protein intake, or digestive issues during treatment
- High stress, poor sleep, or postpartum recovery
What to Do If You Notice Shedding
Don’t stop a prescribed antibiotic on your own. Instead, document when shedding started and how much hair you’re losing, then share that information with your prescriber. If needed, they may review alternatives, check for interacting factors, or order labs (iron/ferritin, thyroid, vitamin D, B12).
Supportive steps that are usually helpful during recovery include:
- Prioritize protein at each meal and include iron- and zinc-rich foods
- Be gentle with styling: avoid tight hairstyles, harsh bleaching, and frequent heat tools
- Treat your scalp kindly: use a mild shampoo and avoid heavy product buildup
- Manage stress and sleep, since both can worsen shedding
- Consider a probiotic or fermented foods if antibiotics upset your digestion (check with your clinician if you have medical conditions or take other medications)
How Long Does It Take for Hair to Grow Back?
If the shedding is telogen effluvium, regrowth often starts once the trigger settles. Many people notice improvement within about 3–6 months, though full density can take longer depending on overall health, nutrition, and genetics. If shedding continues beyond six months, it’s worth getting a professional evaluation to rule out other causes.
When to See a Doctor
Seek medical advice if you have any of the following:
- Patchy hair loss, scalp pain, scaling, or signs of infection
- Hair loss with a rash, swelling, fever, blistering, or breathing difficulty
- Sudden, heavy shedding that continues for more than 6–8 weeks
- History of thyroid disease, anemia, autoimmune conditions, or recent pregnancy
F.A.Q.
Do all antibiotics cause hair loss?
No. Hair loss is not a typical antibiotic side effect. When shedding happens, it’s often temporary and may be related to the illness being treated rather than the medication itself.
Is antibiotic-related hair loss permanent?
Most cases are temporary. Telogen effluvium does not usually damage the hair follicle, so hair typically returns once the trigger is resolved and nutrition is back on track.
Should I take biotin or other supplements?
Supplements can help if you have a confirmed deficiency. If you’re unsure, ask your clinician about checking iron/ferritin, vitamin D, B12, and zinc before starting multiple supplements.
Can I do anything to prevent shedding while I’m on antibiotics?
Focus on basics: finish your prescription as advised, eat enough protein and iron-rich foods, stay hydrated, and keep hair care gentle. If you’ve had repeated shedding episodes, discuss it with a dermatologist.
Talk to a Specialist if Hair Thinning Persists
If shedding continues or you’re worried about ongoing thinning, a dermatologist can help confirm the cause and guide treatment. If you’re exploring clinical options for long-term hair loss, the Hair Center of Turkey team can share information on diagnostic steps and suitable treatment paths based on your situation.
