Rapid weight loss can shift more of your hair follicles into the resting phase — a temporary, reversible cycle dermatologists call telogen effluvium. The Spa Dr.® Hair Serum is doctor-formulated to support visibly fuller-looking hair through life transitions that put your hair cycle under strain.
50 mL · Peptide-powered scalp serum
A 2026 study of 547,993 patients found GLP-1 users were
26% more likelyto experience non-scarring hair shedding within six months.
Source: Akiska et al., JAAD International, February 2026.
Before you spend a dollar on another product, here’s what we know about why this is happening — and the most important word in the conversation: temporary.
Normally, about 10–15% of the hair on your scalp is in the telogen — or resting — phase. After a major physiologic change (rapid weight loss, lower caloric intake, less protein), that number can jump to 30% or more. The result: a wave of diffuse shedding 2–4 months after the change began.
This is the same mechanism behind postpartum hair loss, post-illness shedding, and the shedding people see after rapid dietary changes. It’s diffuse, it’s self-limiting, and in most people it resolves within 6–12 months once the body re-stabilizes.
In other words: your hair is not gone. Your hair cycle is just on pause.
The signal is strongest at higher weight loss percentages. In the largest published study to date, alopecia incidence roughly doubled when users lost more than 20% of their body weight.1
1 Akiska et al., TriNetX multicenter cohort, JAAD International, February 2026.When I formulated this serum, I wasn’t thinking about a single drug or diagnosis. I was thinking about every woman in my practice whose hair cycle was under strain — whether from a major life change, a new medication, or simply the stress of modern living. The goal was a clean, peptide-and-botanical serum that supports the scalp environment during those transitions, not after the damage is done.
Dr. Trevor Cates, ND Naturopathic Physician · Founder, The Spa Dr.®
A water-based peptide and botanical scalp serum, doctor-formulated to support visibly fuller, healthier-looking hair through periods of physiologic change.
Acetyl Tetrapeptide-3 and Red Clover — a biomimetic peptide pairing studied to support the appearance of denser hair density.
Pea Sprout Extract is positioned around the anagen (growth) phase — the same hair cycle phase that telogen effluvium disrupts.
Centella Asiatica, niacinamide, and Panax ginseng support a calmer, healthier-looking scalp — the foundation underneath everything else.
Water-based, doctor-formulated, and built on ingredients with mechanism-of-action studies in the hair-and-scalp literature.
Acetyl Tetrapeptide-3
Biomimetic Peptide
Signals the follicle’s anchoring structure
A biomimetic peptide positioned around supporting the matrix proteins (collagen IV, laminin) that hold each strand in place.*
Pea Sprout Extract
Anagen Support
For the growth phase
The botanical positioned around supporting the anagen (growth) phase ratio — the same phase disrupted by telogen effluvium.*
Red Clover
Trifolium pratense
Hormonal scalp support
A botanical phytoestrogen used in scalp formulas to support a balanced scalp environment.*
Centella Asiatica
Gotu Kola
Soothing & conditioning
A traditional botanical used to soothe the scalp and support a healthy-looking scalp environment.*
*These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.
A short list of what you won’t find in this bottle — and why that matters.
So nothing sits on top of the scalp creating buildup.
Water-based so it absorbs cleanly without coating.
Sensitive scalps need fewer ingredients, not more.
This is a clean cosmetic serum — not a drug, not minoxidil.
In a 90-day brand-conducted study, women applied The Spa Dr.® Hair Serum daily and self-reported on the appearance of their hair.
Reported stronger and more resilient-looking hair
Noticed visibly reduced shedding
Noticed an improvement in the appearance of hair fullness
Based on a 90-day self-reported consumer study. Individual results may vary. Use as directed.
I’m seeing way less hair in my brush.
“I started using this about a month into Wegovy when the shedding really kicked in. After about six weeks of daily use my brush is so much lighter, and the scalp feels healthier.”
My hair looks fuller in the mirror again.
“The shedding scared me. Reading about telogen effluvium and finding this serum was a turning point. Three months in and my hair just looks like itself again.”
Helped my postpartum hair so much.
“Same idea, different season. Postpartum shedding hit like a truck. The serum is the only thing in my routine I really stuck with — my hair feels stronger and the part line looks better.”
My scalp feels so much healthier.
“Doctor-formulated and fragrance-free was what sold me. After perimenopause my scalp got sensitive to everything. This one is the gentlest serum I’ve used.”
Easy daily step that actually fits.
“A few drops to the scalp at night, massage it in, that’s it. No mess, no smell, no greasiness. The simplicity is half the appeal.”
No more visible scalp at the part.
“The first thing I noticed wasn’t length, it was the part line. The scalp showing through bothered me most. After two months I stopped reaching for the powder.”
Verified reviews aggregated across thespadr.com, Amazon and Trustpilot. Individual results may vary.
Telogen effluvium isn’t unique to GLP-1 medications. The same temporary hair-cycle shift happens in postpartum recovery, post-illness recovery, perimenopause, and after any rapid change in diet or stress level. The serum is formulated to support visibly fuller, healthier-looking hair through any season your hair cycle is under strain.
Doctor-formulated peptide-and-botanical scalp serum. Fragrance-free. Free of silicones, oils, sulfates. Backed by a 30-day money-back guarantee.
Shop the Hair Serum — USD 33