How a medicine can make hair fall out
Hair grows in a cycle. Each hair grows for years, rests for a few months, then falls out and a new one takes its place. Some medicines push a large number of hairs into the resting phase at once. About two to four months later, all those hairs shed together. Doctors call this telogen effluvium. It is the most common kind of drug-related hair loss.
A second, more dramatic type is anagen effluvium. Here the drug stops the hair from growing while it is in the growing phase, and the hair breaks off within days or weeks. This mostly happens with chemotherapy for cancer.
The good news is that both types are usually temporary. Once the medicine is stopped or changed, the hair cycle resets and growth returns, though it may take six months or more to look normal again.
Common medicines linked to shedding
Blood thinners such as warfarin and heparin can cause shedding, usually a few months after starting. Beta blockers used for blood pressure, like metoprolol and propranolol, are another known cause, though it is not common.
Isotretinoin, the strong acne pill, and very high doses of vitamin A can cause hair thinning while you take them. Some seizure medicines, especially valproate, are a well-known cause. Lithium, used for bipolar disorder, is linked to hair loss in a meaningful share of patients.
Antidepressants, including fluoxetine and sertraline, can cause shedding in a small number of people. Some cholesterol medicines and some arthritis medicines like methotrexate are on the list too. Starting, stopping, or switching hormonal birth control can trigger a shedding wave as hormone levels shift.
Hormones and hair loss
Testosterone and anabolic steroids speed up male pattern hair loss in people who are genetically prone to it. The body turns testosterone into DHT, and DHT shrinks sensitive follicles. This type of loss is not a shedding wave. It is the usual pattern of a receding hairline or thinning crown, just arriving sooner.
Men on testosterone replacement therapy should know this risk. If your father or brothers lost their hair early, you are more likely to see it. Finasteride, which blocks DHT, is often prescribed alongside testosterone for this reason.
What about weight-loss injections?
Hair loss is a reported side effect of the GLP-1 medicines used for weight loss. In the STEP 1 trial of semaglutide (the drug in Wegovy and Ozempic), about 3 percent of people taking the drug reported hair loss, compared with about 1 percent on placebo. In the SURMOUNT-1 trial of tirzepatide (the drug in Zepbound), around 5 percent reported it, compared with under 1 percent on placebo.
Doctors believe this is not the drug attacking the hair. It is the fast weight loss. Losing a lot of weight quickly is a known trigger for telogen effluvium, and the same thing happens after weight-loss surgery. The shedding usually starts a few months into treatment and settles down as weight stabilizes. Eating enough protein and keeping iron, vitamin D, and zinc in normal range can help.
At Zen IV Spa we prescribe compounded semaglutide ($199 a month), compounded tirzepatide ($299), and retatrutide ($249). These compounded versions are not FDA-approved. The hair loss risk is the same kind of weight-loss-related shedding seen with the brand drugs, and our medical director can add hair treatment to your plan if it shows up.
What to do if you notice shedding
First, do not stop a prescribed medicine on your own. Some of these drugs are protecting your heart, your mood, or your brain. Talk to the doctor who prescribed it. Often there is a similar drug that is less likely to affect hair, or the dose can be lowered.
Ask for basic blood tests. Low iron, low thyroid, and low vitamin D cause the same kind of shedding and are easy to fix. Timing matters too. If the shedding started two to four months after a new medicine, that medicine is a likely suspect. If it started much later, something else may be going on.
If the loss looks like a pattern, with a receding hairline or thinning crown, the medicine may have simply sped up hair loss that was going to happen anyway. In that case, minoxidil and finasteride are the proven treatments, and they work whether or not a drug triggered the start.
Hair loss help from Zen IV Spa
If a medicine or fast weight loss has thinned your hair, our medical director can review your list, order labs drawn at home by a nurse, and build a plan. Zen IV Spa offers finasteride for $49 a month, oral minoxidil for $59, a topical minoxidil spray for $69, or the full program for $149, shipped anywhere in New York and New Jersey. Start at /hair-loss/, call (332) 239-2005, or book a free video visit at https://zenivspa.zenoti.com/webstoreNew/services.
Common Questions
How soon after starting a medicine does hair loss begin?+
Usually two to four months later for telogen effluvium. Chemotherapy-related loss starts within a few weeks.
Will my hair grow back if I stop the medicine?+
In most cases, yes. Expect three to six months before you see new growth and up to a year for full recovery.
Does Ozempic cause permanent hair loss?+
No evidence suggests it is permanent. The shedding is tied to rapid weight loss and usually stops once weight levels off.
Can I take finasteride while on another medicine that causes hair loss?+
Often yes. Finasteride has few drug interactions, but always tell your provider everything you take.
Do vitamins prevent drug-related hair loss?+
Only if you are deficient. Extra biotin or vitamins do not block a medicine's effect on the hair cycle.
Sources: FDA prescribing information for Wegovy (semaglutide) and Zepbound (tirzepatide); Wilding et al., STEP 1 trial, NEJM 2021; Jastreboff et al., SURMOUNT-1 trial, NEJM 2022; American Academy of Dermatology on medication-induced hair loss; Mayo Clinic on telogen effluvium.
All treatments are medical services. Every guest is screened, and every treatment is prescribed by a licensed provider. Nothing on this page is medical advice for you personally, and the opinions summarized here belong to the doctors named, not to Zen IV Spa. Talk to a provider before starting or stopping anything.
