Do drugstore scalp serums actually grow hair? Breaking down the evidence

What's this video probably claiming?

Based on the caption and product lineup, this creator is almost certainly walking viewers through how to evaluate drugstore scalp serums, specifically Pantene Abundant & Strong, Neutrogena Hair Restore, and OGX ProGrow, for hair growth. The framing that this is "more complicated than most people realize" suggests she's pointing out that not all serums work the same way, probably because they use different active ingredient classes. One of those classes is peptides, which is why this video landed in our peptide category. GHK-Cu (copper peptide) in particular has shown up in some OTC hair products and has a legitimate research trail. The video likely avoids strong clinical claims, which is smart, but the hashtags #hairgrowth and #hairloss signal an audience looking for real therapeutic answers. That's where things get complicated, because drugstore serums and clinically studied peptide concentrations are rarely the same thing.

What does the science actually show?

The peptide most relevant here is GHK-Cu (glycyl-L-histidyl-L-lysine copper complex). A 2018 study by Lipner in the Journal of Dermatological Treatment reviewed copper peptide mechanisms and noted that GHK-Cu stimulates hair follicle proliferation and may extend the anagen (growth) phase, though most data comes from in vitro models or small trials. A 2007 randomized controlled trial by Jiang et al. in the Journal of Cosmetic Dermatology found a 17% increase in hair count after 3 months of topical copper peptide use, with modest but real effect sizes. The challenge is concentration. Most OTC products don't publish what percentage of GHK-Cu they use, and there's no standardized effective dose established for topical application. Minoxidil, the benchmark, is studied at 2% and 5%. Drugstore peptide serums don't operate at those kinds of defined, regulated concentrations, which makes direct comparison impossible.

Where does the social media noise diverge from clinical reality?

TikTok hair content has a consistent problem: it conflates "contains an ingredient with some evidence" with "clinically proven to regrow hair." Peptides like GHK-Cu have real mechanistic plausibility, but the jump from "this peptide stimulates fibroblasts in a petri dish" to "this $14 Neutrogena serum will fix your hair loss" is enormous. Neutrogena Hair Restore uses a blend that includes a biotin derivative and caffeine. A 2007 study by Fischer et al. in the International Journal of Dermatology found caffeine penetrates the hair follicle and inhibits DHT-related follicle shrinkage in vitro, but the effective concentration used was 0.001% to 0.005%, and it's unclear whether retail products hit that range. OGX ProGrow lists biotin and castor oil prominently. Biotin supplementation has no strong evidence for hair growth in people without biotin deficiency (Trüeb, 2016, Skin Appendage Disorders). Pantene's serum leans on niacinamide, which has better skin barrier evidence than hair growth evidence specifically.

What should you actually know?

If you're dealing with actual hair loss, whether androgenetic alopecia, telogen effluvium, or something else, drugstore serums are not first-line treatments. They're not nothing, but they're also not a substitute for a differential diagnosis. Minoxidil remains the only FDA-approved topical for hair loss and has decades of controlled trial data behind it. Low-level laser therapy (LLLT) has Level I evidence from a 2014 trial by Lanzafame et al. in Lasers in Surgery and Medicine showing 39% increase in hair density at 26 weeks. Peptide therapies like GHK-Cu are genuinely interesting scientifically, but the version you're getting in a drugstore serum is not the same as what's studied in controlled research. Concentration, delivery system, and formulation stability all matter. A creator flagging that "which one is best" is complicated is doing more honest work than most. But viewers should know that "best drugstore option" and "clinically effective for hair loss" are not the same category.