If you're in your 30s or 40s and your hair has started to look different, there are really three things it could be: ordinary shedding, the slow changes that come with age, or the early stage of pattern hair loss. In the drain they can look much the same. Only the third keeps going if you leave it, though, which is why it's the one I'd most want to catch early.

How much shedding is normal

The American Academy of Dermatology puts normal shedding at roughly 50 to 100 hairs a day. I don't find that number very useful in practice, because nobody counts, and how much you actually see depends heavily on things that have nothing to do with hair loss. If your hair is past your shoulders and you only wash twice a week, every wash pulls out several days' worth of hairs that had already come loose and were just caught in the rest, so a big tangle in the drain on wash day can be completely normal.

So I'd judge shedding against your own baseline rather than a number. A few weeks of clearly more hair than usual is worth noting. If it's the amount you've always seen and you're just watching more closely now, it usually isn't a concern.

Changes that come with age and aren't a problem

A man who puts a photo from 18 next to one from 28 will often see his temples sitting a little higher. If that change happened once, by a small amount, and has stayed put since, it's almost certainly the normal shift from a juvenile hairline to a mature one. When the temples keep going back year after year, deepening into an M, or the crown starts thinning as well, that's pattern loss rather than maturing.

I'd also expect hair to grow a bit more slowly and come in a little finer as you get older, in men and women alike, and grays to feel coarser than the hair around them. I mention these because they change how hair looks and styles, and people sometimes mistake that for loss.

How common pattern hair loss is at this age

In men, the classic estimate goes back to the dermatologist James Hamilton, who found that somewhere between 30% and 50% of men had pattern hair loss by age 50. Later studies have landed in similar territory. When researchers in India examined 1,005 men aged 30 to 50 from the community around their hospital, 58% had some degree of it. An Australian study of men aged 40 to 55 found that 31% already had thinning at the crown or more extensive loss.

For women the numbers start lower and rise steadily. A community study in Maryborough, Australia, found that 12% of women had some degree of female pattern hair loss by age 29, and 25% by age 49.

Pattern loss is common at this age, then, though plenty of people get through their 30s and 40s with very little change, which is part of why it's worth finding out which group you're in instead of assuming.

Signs that point to more than normal aging

In men, the pattern usually announces itself at the temples and crown. Temples that keep receding past where a mature hairline would stop, especially into a deepening M shape, are one signal. A crown where scalp starts to show under overhead light is another, and it's often spotted first by someone standing behind you, or in a photo.

Women tend to see it along the part. It looks a little wider each year, and more scalp shows on either side of it. The front hairline usually stays where it was, which is one reason women often don't recognize pattern loss for what it is, and why the first clue is sometimes just a ponytail that feels thinner in the hand.

When a dermatologist examines a scalp for early pattern loss, what we're looking for under magnification is variety in hair thickness. If I see short, fine, almost see-through hairs mixed in among normal ones at the part or crown, that tells me follicles are shrinking, often well before the hair looks thin to anyone else.

If you find a round, smooth bald patch, or your scalp is sore, itchy, or scaly, or your hairline is thinning along with your eyebrows, I wouldn't wait and watch. Those need a dermatologist within weeks, since some of the conditions behind them, alopecia areata among them, need specific treatment and a few can scar.

	Usually normal	Worth checking
Shedding	Your usual amount	Weeks of clearly more, all over
Hairline (men)	Small shift, then stops	Temples keep receding
Part (women)	Unchanged in photos	Wider year to year
Hair texture	Slightly finer overall	Short, wispy hairs among normal ones
Scalp	Calm	Patches, itching, scaling

Other causes that show up in these decades

Pattern loss and post-illness shedding aren't the only explanations in these decades. Pregnancy is the obvious one, with shedding that usually starts a few months after delivery and eases within the year. If your periods have gotten heavier, I'd want your ferritin checked before blaming anything else, because heavy bleeding slowly drains iron stores. If you also have irregular cycles, adult acne, or new facial hair, polycystic ovary syndrome is worth asking about, since its raised androgens can bring pattern thinning on early. And if you're unusually tired or your weight has shifted without explanation, thyroid disease, which is far more common in women, belongs on the list too.

In men, sudden shedding in these years more often traces back to something simple, like an illness, a big swing in weight, or a new medication, and in anyone, a daily habit of tight braids, ponytails, or extensions can thin the hairline over time. A basic blood panel for iron and thyroid covers most of the medical possibilities, and it's a reasonable first thing to ask your doctor for if your shedding is new or heavy.

When to act

My view on timing comes down to one fact about pattern hair loss: it tends to keep progressing. The AAD puts it plainly, noting that many people with hereditary hair loss continue to lose hair without treatment. And nearly everything we can offer works better at holding on to hair than at regrowing hair that's been gone for years. So if the signs above point toward a pattern, starting earlier usually means keeping more.

Shedding after a clear trigger is different. If you know you had a bad illness or a rough few months and the hair loss started a couple of months later, giving it three to six months to settle is reasonable, as long as your part and crown aren't changing. If it's still going past six months, or the thinning starts to concentrate in one area, that's the point to get it looked at. Dermatologists call this kind of delayed shedding telogen effluvium, and the AAD notes it often stops on its own once the trigger has passed, though now and then it uncovers a pattern that had been developing underneath.

Photos make all of this easier to judge. One picture of your part or crown a month, in the same spot and light, will tell you more by month three or four than any amount of checking the mirror day to day. If the pictures look the same and only the shedding fluctuates, you're probably looking at a temporary phase. If the scalp is gradually showing more, that's a pattern.

If it does turn out to be pattern loss, topical minoxidil is the over-the-counter option with the most evidence behind it. Women use the 2% strength and men the 5%, and its FDA approval covers mild-to-moderate androgenetic hair loss, the medical name for pattern loss. Give it several months before deciding whether it's working. I'd hold off during pregnancy, which matters for a lot of women in this age range. For men there's also finasteride, a prescription pill whose benefits and side effects are worth going through with a doctor, and which isn't for women who are or could become pregnant.

Where MDhair fits

My team and I ran a six-month clinical trial of MDhair's personalized regimen, published in the Journal of Drugs in Dermatology in 2025. It looked at hair loss broadly rather than any one age group. We compared our regimen against one specific competitor, the leading hair loss supplement brand, so I'd read what follows as support for personalizing a routine and not as a forecast for your own hair. At 90 days, hair growth had improved about 2.8 times as much. For hair quality the figure was about 3.0 times.

A quick word on labels. Minoxidil is the one product we sell with OTC drug status, approved for mild-to-moderate androgenetic hair loss. Everything else in the range, the serums, shampoos, and supplements, is sold as a cosmetic or a supplement. So none of it is meant to diagnose, treat, cure, or prevent disease, and the FDA hasn't reviewed what's claimed for the supplements. If you're pregnant or nursing, or being treated for something, check with your doctor before adding a new product. Stop any product that irritates your scalp.

For people at the early stage, our Essential Regrowth Kit ($66) is the entry point into an MDhair regimen. Like our other kits, it's customized: the free AI hair and scalp assessment, a short quiz plus a scalp photo, determines what goes into it based on your hair type, your scalp, and the likely cause of your hair loss. Every regimen also comes with unlimited chat access to our dermatologist team, which is useful when you're not sure whether what you're seeing is normal.

Dr. Yoram Harth is a board-certified dermatologist and Co-Founder and Chief Medical Officer of MDalgorithms Inc., the company behind MDhair and MDacne. A magna cum laude graduate of Tel Aviv University's Sackler School of Medicine, he trained in dermatology at Rambam Medical Center and completed a research fellowship at Columbia-Presbyterian Medical Center in New York. His work spans phototherapy, photodynamic therapy, and AI-personalized skin and hair care.

Sources

Studies were located through PubMed and the publishing journals' own sites.

1. American Academy of Dermatology. Do you have hair loss or hair shedding? aad.org
2. Endotext. Male androgenetic alopecia. National Library of Medicine Bookshelf. ncbi.nlm.nih.gov
3. Krupa Shankar D, Chakravarthi M, Shilpakar R. Male androgenetic alopecia: population-based study in 1,005 subjects. Int J Trichology. 2009;1(2):131-133. doi:10.4103/0974-7753.58556
4. Gan EK, Sinclair RD. Prevalence of male and female pattern hair loss in Maryborough. J Investig Dermatol Symp Proc. 2005;10(3):184-189. doi:10.1111/j.1087-0024.2005.10102.x
5. Bhardwaj V, Rodgers N, Harth O, Harth Y. Artificial intelligence-based personalization of treatment regimen for hair loss: a 6-month clinical trial. J Drugs Dermatol. 2025;24(3):233-238. doi:10.36849/JDD.8611

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