From a $24 staple to a biotech newcomer with a 190-person clinical trial — these are the 6 hair serums GLP-1 users should know about during their weight loss journey.
If you’ve been losing weight quickly, you may have started noticing things like a thinner ponytail, more hair in the shower drain, or hair that just doesn’t look as thick as it used to. This type of shedding has a name — telogen effluvium: a temporary shedding phase that can follow any significant change to the body — rapid weight loss, childbirth, extreme stress, etc. The nutrient shifts that come with eating less can play a part too.
The good news is that GLP-1 hair thinning doesn’t have to be a part of your GLP-1 journey. This kind of shedding is usually temporary, but hair recovery takes time. So if you’re reading this, it’s likely that the time to act on it is now — here are 6 hair serums you should be using in 2026.
RE:YOU is the newest and most exciting name on this list, and comes from the emerging “biotech-beauty” space. I found out about RE:YOU through a friend in the beauty space who got sent a PR package:
RE:YOU’s hair serum is built around proprietary NOVOGRO™ technology — key molecules developed specifically for hair-thinning and selected from a screening of over 2 million molecules. This technology was developed by their own team of PhD scientists and represents a refreshing approach to product development compared to competitors picking out the same handful of botanicals for their formulations.
The mechanism is also worth noting: the serum targets dermal papilla cells at the root of hair follicle growth, as well as the scalp environment. Another thing I love is that they thoughtfully address some of the cons you see in other products like fragrance, texture, hair compatibility, etc. Though a newcomer to the category, RE:YOU is an exciting look at what happens when biotech comes to beauty.
Rogaine’s hero ingredient is minoxidil, the current gold standard for treating hair thinning. Minoxidil is the only over-the-counter ingredient approved by the FDA for hair regrowth, and it supports hair growth by widening blood vessels and increasing nutrient flow towards your hair follicles.
Something to note if you’re already shedding from rapid weight loss is the initial “dread shed” that typically occurs when users first start using minoxidil. It’s expected but can make the first few weeks difficult for users who start using it because of hair shedding in the first place. Olivia Harper from TBB described her own emotional experience:
You’re already paying enough to be on a GLP-1 — this doesn’t add much to the pile. Like many, this was one of the first hair serums I’ve tried due to its low barrier to entry; no other product that is worth your while comes close to the price at $24 per bottle.
On top of all that, the texture feels lightweight and I didn’t feel the need to wash my hair between uses. Negative reviews cite irritation and discomfort, but I personally didn’t notice when using it — just something to be aware of. This is definitely a bang for your buck option and great for anyone who wants to try out a hair serum without committing to a premium routine.
If you’ve been researching serums since your weight started dropping, you’ve almost certainly passed by Vegamour already. Their GRO line is a popular option for anyone looking for support across their entire hair routine — it includes a shampoo, conditioner and gummy supplement, each developed to complement the others and make up a cohesive routine.
Naturally they are keen on selling the full set, so it’s unclear how results compare with the serum alone against using it with the rest of the product line. Additionally, one of the main complaints across users is the greasy texture. Beauty writer, Cheryl Maday notes:
KilgourMD splits hair treatment into two parts, quite literally: one serum for prevention (slowing shedding) and one serum for treatment (activating growth). Several users complain about the two-bottle structure and then added cost from buying two serums instead of just one.
On the flip side, the two-bottle structure means you can lean on one or both depending on where you are in your hair journey; for GLP-1 shedding specifically, being able to lean harder on the prevention side while the shedding phase runs its course can be an advantage.
I initially bought KilgourMD’s serum because, like RE:YOU, it has strong scientific backing compared to other products in the category. The first thing I noticed, like many other users, was the greasy texture and off-scent of the serums. Not a deal-breaker for me, but something worth noting if those are things you care about.
OneSkin’s proprietary peptide, OS-01, targets cellular senescence — the point in a cell’s life where damaged or aging cells stop dividing but stay alive (anyone interested in longevity is likely familiar with the term). OneSkin has built an entire scientific program around their OS-01 molecule across their skincare range, and they’re now applying that same technology to hair. Charlotte from TBB says:
OneSkin includes a dermaroller with its multi-month plans, so users can effectively replicate the results seen in their clinical study. The microneedling step has made some potential customers hesitant, as well as the twice-a-day routine among users who already struggle to keep a daily routine on track. That being said, the serum is well-positioned for users not only experiencing weight-loss related thinning, but also age-related thinning, and if you’re already thinking about cellular-level aging for your skin, this is the same science applied upward.
Whatever you land on, the most useful thing I can tell you is this: give it time.
Every study behind the products on this list ran at least 90 days, and several ran six months — there’s a reason for that. The first stretch is the hardest, and it’s where most people give up. You start wondering whether it’s even working, and you quit right before there’d be anything to see.
So the hardest part of this isn’t choosing which one, it’s waiting for it to do its work.
