There comes to a point in your life when you ask yourself: Why am I losing so much hair? It’s normal—even expected—for some of your hair to fall out daily. But when more strands than usual start collecting in your comb or clogging your shower drain, it’s much harder to stay chill. Is it stress? Your shampoo? Genetics and Father Time finally taking their toll?
The good news: Not all hair shedding is full-blown hair loss. And figuring out which one you’re dealing with is the first step toward treating it.
Hair shedding vs. hair loss
Most people think hair shedding and hair loss are one and the same. In reality, they’re two separate beasts.
According to James Kilgour, MD, board-certified dermatologist and founder and CEO of KilgourMD, hair shedding refers to the normal release of hairs that have reached the end of their growth cycle. “This becomes more noticeable when a larger than normal amount of follicles enter the resting phase at the same time, resulting in a condition known as telogen effluvium,” he says.
Hair loss works differently. In the case of androgenetic alopecia (a.k.a. male pattern hair loss), the hairs don’t simply fall out. The follicles themselves begin to shrink and eventually produce thinner, weaker hairs before shutting down altogether.
Put simply, shedding is what you notice on your bathroom floor. Hair loss, meanwhile, is what you notice in the mirror—like a widening part, a receding hairline, or gradual thinning.
What causes hair shedding?
It’s normal to lose anywhere from 50 to 150 hairs a day. According to Carson Kirkpatrick, MD, dermatologist at Montefiore Einstein Advanced Care, we have about 100,000 follicles on our scalp, making that amount fairly negligible. But the red flags are raised when you shed 200-plus hairs daily, or you suddenly see clumps in the drain or on your brush.
The upside? Telogen effluvium, or bouts of excessive shedding, is usually temporary. The tricky part is that the shedding doesn’t start right away. “Sudden, diffuse shedding tends to start two to four months after a major stressor: an illness, surgery, or major weight loss,” including that from GLP-1 use, says Dr. Kirkpatrick. Additional culprits include chronic stress, highly restrictive diets, certain medications, and significant hormonal changes, adds Dr. Kilgour.
Unlike pattern hair loss, telogen effluvium typically resolves on its own—often within six to nine months—once the trigger passes or is addressed.
What causes hair loss?
By and large, androgenetic alopecia is the most common cause of hair loss in men. Per Dr. Kirkpatrick, the condition affects at least half of men and up to 80% of men by age 80. “It’s driven by dihydrotestosterone (DHT), which is converted from testosterone and binds to receptors on genetically vulnerable follicles, shrinking them over time,” he says. You can curse your genetics for this one, as a strong family history of it raises your likelihood of following suit.
But genetics are only one part of the equation. Hair loss tends to be multifactorial, and a handful of other drivers can accelerate the process.
According to Dr. Kilgour, deficiencies in iron, zinc, vitamin D—as well as inadequate protein intake (assuming you somehow escaped the high-protein craze)—can impair healthy hair growth. Similar to telogen effluvium, chronic stress is a common culprit, as it disrupts the hair cycle and exacerbates underlying pattern hair loss. Additional lifestyle triggers include smoking and excessive UV exposure (which aren’t doing your skin any favors, either).
Dr. Kirkpatrick adds that your grooming routine can also do real damage. “Chronic tension from tight braiding or styling causes traction alopecia, while excessive brushing, heat, and chemical treatments weaken the hair shaft itself,” he says. Your scalp health matters, too. Chronic low-grade inflammation and an unhealthy scalp environment “can compound genetic susceptibility and worsen hair loss progression,” adds Dr. Kilgour.
Medical conditions—including thyroid disease, autoimmune disorders, and severe infections—can also accelerate hair loss. So, too, can certain medications. Per Dr. Kilgour, these include some antidepressants, blood pressure medications, and anticoagulants.
The best treatments for hair loss
If you (and your derm) have uncovered that hair loss—not shedding—is the issue, it’s best to intervene early and tackle it on multiple fronts. Unlike temporary shedding, hair loss requires a more deliberate approach.
Lifestyle changes—like eating a nutrient-dense diet and adopting smarter grooming habits—are a good start. But if you’re dealing with true hair loss, they usually won’t reverse it on their own. Unsurprisingly, prescription medications will be your strongest line of defense. Per Dr. Kirkpatrick, topical minoxidil (which extends the hair growth phase of the hair cycle) and oral finasteride (which blocks the enzyme that produces DHT) remain the gold standards. Oral minoxidil is another option that derms prescribe for patients who dread applying the solution to their scalp daily.
“Beyond those, dutasteride is a more potent DHT blocker that may outperform finasteride, especially in the frontal area,” says Dr. Kirkpatrick. (Just note that it’s used off-label for this purpose.) “There’s also a topical finasteride for men wary of systemic effects, low-level laser therapy devices, and platelet-rich plasma (PRP) injections, though the evidence for some of these is more limited.”
The earlier you treat hair loss, the better your odds are. “If follicles are still present and producing even very fine hairs, there is often an opportunity to improve density and slow progression,” says Dr. Kilgour. On the other hand, your chances of reviving a hair follicle after years of inactivity are slim to none. “At that advanced stage, hair transplantation, which relocates DHT-resistant follicles from the back of the scalp, becomes the realistic option,” says Dr. Kirkpatrick.
The takeaway is simple: Don’t wait. If you notice your hair changing, see a dermatologist. It’s a lot easier to save follicles than to resurrect them—not to mention cheaper than a trip to Istanbul.