Why your hair is shedding, and what actually helps

Hair disorders make up a significant part of what I treat in my practice, and hair loss can be incredibly frightening when it happens. The first useful step is understanding what type of shedding you are experiencing. Let’s first understand the normal cycle of hair growth.

How the hair growth cycle works

Hair does not grow continuously. Every follicle moves through a cycle, and at any given moment your follicles are all at different points in this cycle. Anagen is the growing phase, and it lasts years, which is why most of the hair on your head is this phase at any given time. Catagen is a brief transitional phase of a few weeks, when the follicle detaches from its blood supply. Telogen is the resting phase, roughly three months, at the end of which the hair releases from the follicle and a new one begins growing in its place. Shedding is not a malfunction. It is the last step of a normal cycle, and losing somewhere around fifty to one hundred hairs a day is simply what a healthy scalp does.

Telogen effluvium, or sudden shedding

Telogen effluvium is what happens when that timing gets disrupted. Something pushes an unusually large number of follicles out of the growing phase and into the resting phase all at once, and then, about three months later, they all release together. This is the shedding that frightens people: hair coming out in the shower, a visibly thinner ponytail, clumps on a pillow. The lag is the part not everyone knows about, and it matters, because it means the cause is usually something that happened a season ago rather than anything you did last week.

The usual triggers are the significant ones: illness, surgery, a major stressor, childbirth, a thyroid change, a new medication, a crash diet. Anything that asks the body to reprioritize will deprioritize hair, because hair is metabolically expensive and not essential. That is also the honest reassurance in this diagnosis. Telogen effluvium is a disruption of timing rather than damage to the follicle, and it regrows.

GLP-1 medications and hair loss

Which brings me to the reason I am writing this now. GLP-1 medications have become one of the most common causes of telogen effluvium I see, and the mechanism is worth understanding with precision. It is not the drug attacking hair follicles. It is rapid weight loss, which does this regardless of how it is achieved, and it has always done it after bariatric surgery and severe caloric restriction. What compounds it on these medications is intake: appetite drops sharply, and protein and micronutrients usually drop with it, often well below what hair needs. So you have a metabolic shock and a nutritional gap arriving together.

It is worth saying that the picture here is genuinely mixed rather than all bad. These medications have anti-inflammatory effects, and inflammation is unhelpful for follicles. They can also improve hormonal and metabolic imbalances that accompany excess weight, and those imbalances are themselves a driver of hair thinning in some patients. So there are plausible mechanisms by which GLP-1s could eventually support hair growth rather than harm it, and some patients do better on the other side of the transition than they were before it. What people experience in the first several months is usually the shedding, not the longer arc.

Two things I would add for anyone in that situation. Slower weight loss produces less shedding, and deliberately protecting nutritional intake is hugely important for many reasons, including protecting your hair. And if the hair does not fully recover once weight stabilizes, that is worth investigating rather than accepting, because rapid loss can also unmask a pattern hair loss that was quietly present already. Those are different diagnoses with different treatments.

The labs worth running first

Before treating anything, it is worth ruling out what can be corrected. The lab tests I often order include a complete blood count, iron studies with ferritin, a full thyroid panel, vitamin D, zinc, and depending on the history, hormonal studies. Ferritin is the one most often missed: it can sit inside the normal reference range and still be too low for hair, which needs more than the rest of the body does. Correcting a deficiency is the most effective hair treatment there is, and no serum will outperform it. It is also worth saying that there are many other causes of hair loss entirely separate from telogen effluvium, some of them autoimmune, hormonal, or scarring, and they look different under examination and are treated differently. That is the real argument for being evaluated by a dermatologist: not only to choose the right treatment, but to be certain the right condition is the one being treated.

What actually helps

Once that is addressed, the things I recommend are these. A well-formulated hair supplement, Nutrafol being one I reach for consistently; red and orange light devices, which have real evidence behind them and may be the most underrated option available; they simply require consistency over months, and making sure to choose the right device, that is, one backed by clinical studies. Topical growth serums can be a very helpful addition, when formulated correctly, and an over-the-counter topical minoxidil serum is where most people should start. Scalp stimulation, which encourages blood flow to the scalp, is pleasant and does no harm. Minoxidil works equally well whether it is taken orally or used topically. I urge you get it through a board-certified dermatologist who can look at your scalp first and confirm what is actually happening, prescribe the correct concentration and perhaps even compound it with other helpful ingredients, and of course monitor carefully for side effects. In-office procedures are worth asking about too, including PRP injections, which can be genuinely helpful in the right patient.

Prescription options

There are also prescription options beyond minoxidil, including spironolactone and finasteride, and they can be very effective in the right patient. They are also medications with the potential for serious side effects and have real considerations around hormones, pregnancy and monitoring, so they belong in a conversation with a physician who knows your history rather than in an article. I mention them only so you know they exist and can ask.

How long regrowth takes

As for the timeline, be patient in a way nobody wants to be. Shedding typically slows within three to six months of the trigger resolving, and regrowth takes a further six to twelve months to be visibly obvious, because hair grows about a centimeter a month and that is not negotiable. The short new hairs along your hairline are the first good sign, and they usually appear before anything looks different in a photograph.

A note, and a firmer one than usual: hair loss has many causes, some of which need a proper medical workup and a few of which are scarring and time-sensitive. This article is general education, not medical advice, and it cannot tell you which kind you have. If your hair is shedding heavily, thinning in a pattern, or your scalp is painful, itchy or visibly changing, please see a board-certified dermatologist in person rather than treating it yourself.