Thinning hair can feel entirely out of your control, especially when it starts seemingly out of nowhere. The underlying causes can be hard to determine, whether stemming from stress, hormonal shifts, or nutritional gaps. The good news is that there are plenty of solutions out there, so it comes down to finding one that actually works.

Peptides are just beginning to gain popularity as the go-to ingredient for fuller hair. Some options come as oral capsules, others as drink powders, and some as topical serums you massage into your scalp. Every choice claims to help, making it difficult to decide which one actually deserves a spot in your routine.

We put OMI Hair Growth Peptides, Neutrogena Hair Restore Pro-Collagen Peptide Supplement, The Ordinary Multi-Peptide Serum for Hair Density, and Vegamour GRO Hair Serum head-to-head. We judged each on formulation, research & third-party testing, routine & convenience, and price. One came out as the clear winner. Read on to find out which.

What to Look For in Hair Growth Peptides

Our comparison focused on four questions:

• Ingredients and formulation: The best products name their peptides, pair them with supporting nutrients or ingredients, and disclose how much of each they contain.
• Supporting research: Results measured against a placebo carry far more weight than users simply reporting how their hair looks and feels.
• Convenience and tolerability: The routine has to be easy enough to maintain every day for months, without ingredients that are likely to irritate your scalp or further problems.
• Price and value: Results can take months, so what counts is the ongoing cost of daily use and what you get for that money.

Hair Growth Peptide Products Compared

Ingredients & Formulation: OMI Hair Growth Peptides Wins with the Most Advanced Formulation

🥇 The winner: OMI Hair Growth Peptides. OMI combines 500 mg of IFP-131 (its patented keratin peptide) with B vitamins, biotin, zinc, and copper. Since hair is made mostly of keratin, a keratin-derived peptide provides your body with building blocks that match what it's actually making, and the supporting nutrients are commonly linked to healthy hair.¹

🥈 Runner-up: Neutrogena Hair Restore Pro-Collagen Peptide Supplement. Each packet provides 2.5 g of cow-derived collagen peptides and 70 mg of vitamin C. Neutrogena is clear about its amounts, and collagen does supply amino acids your body can use to build protein. But collagen is a general-purpose protein, not one aimed at hair the way a keratin peptide is.²

🥉 Third: The Ordinary Multi-Peptide Serum for Hair Density. This serum packs in two lab-made peptides (biotinoyl tripeptide-1 and acetyl tetrapeptide-3), 1% caffeine, and several branded plant extracts. Putting actives straight onto the scalp puts them where hair grows, which is a real plus. The catch is that individual peptide doses aren't disclosed, so it's hard to know how much of each you're getting.³

❌ Fourth: Vegamour GRO Hair Serum. GRO combines three peptide complexes with caffeine and plant extracts like turmeric and mung bean sprout extract, but like The Ordinary, it doesn't list peptide amounts. It also contains denatured alcohol (a drying type of alcohol) and added fragrance.⁴ Denatured alcohol can dry out skin and weaken its protective barrier, leading to irritation and redness.⁵ Fragrance is also one of the most common causes of allergic skin reactions.⁶ That matters more for a leave-in serum that sits on your scalp all day, especially if your scalp is sensitive or dry.

Research & Third-Party Testing: OMI Wins with Placebo-Controlled Evidence

🥇 The winner: OMI Hair Growth Peptides. OMI's own 90-day study found women with stressed hair shed up to 47% less hair than with a placebo.⁷ It also points to two published keratin studies that found it reduced hair loss, one by the keratin maker and one run by an independent lab.⁸⁻¹⁰ OMI is also third-party tested.⁷

🥈 Runner-up: Vegamour GRO Hair Serum. Vegamour cites a 120-day survey of 40 users, most of whom said they saw less shedding and better-looking hair. There was no placebo group, and there is no published clinical study or third-party testing.⁴

🥉 Third: Neutrogena Hair Restore Pro-Collagen Peptide Supplement. Neutrogena says it's clinically shown to promote thicker hair in 16 weeks, but there are no available study details. It has also not undergone third-party testing.²

❌ Fourth: The Ordinary Multi-Peptide Serum for Hair Density. There's no clinical data on this serum.¹¹ It leans on branded ingredients like Redensyl, Procapil, and Capixyl, whose research was mostly small and paid for by the companies that make them.¹² No third-party testing is listed.³

Routine & Convenience: Neutrogena Wins with the Most Flexible Routine

🥇 The winner: Neutrogena Hair Restore Pro-Collagen Peptide Supplement. Stir one packet into a hot or cold drink each day. It's unflavored, so it disappears into your morning coffee or a smoothie, and you can take it any time, with no meal to plan around.²

🥈 Runner-up: OMI Hair Growth Peptides. You take two capsules a day, and nothing goes on your hair, so your styling and wash days stay the same. It's the best fit if you'd rather swallow a capsule than add another product on your scalp. It's only a little less flexible than Neutrogena because it needs to be taken with food.⁷

🥉 Third: Vegamour GRO Hair Serum. Massage a dropperful into your wet or dry scalp daily and leave it in. If you're worried about a greasy scalp, it's water-based and fast-absorbing, and claims it won't leave hair feeling greasy.⁴,¹³ Still, it's an extra step, and its alcohol and fragrance may bother a sensitive scalp.

❌ Fourth: The Ordinary Multi-Peptide Serum for Hair Density. Apply a few drops to a clean, dry scalp each night and leave it in, which rules out evening showers.¹¹ This serum is the least-time flexible and most challenging to maintain consistency with.

Price & Value: The Ordinary Wins with the Lowest Daily Cost

🥇 The winner: The Ordinary Multi-Peptide Serum for Hair Density. A 60 mL bottle costs $24, the lowest upfront price here.³ The brand doesn't say how long it lasts, but some users estimate about three months of daily use. That works out to roughly $0.27 per day, the lowest daily cost of the four.

🥈 Runner-up: Neutrogena Hair Restore Pro-Collagen Peptide Supplement. At H-E-B, 20 packets cost $19.97, just under $1.00 per day. Each packet is one day's serving, so this is the easiest daily cost to determine according to dose.¹⁴

🥉 Third: Vegamour GRO Hair Serum. A single one-month supply costs $64 (about $2.13 per day).⁴

Fourth: OMI Hair Growth Peptides. A month costs $77 by subscription (about $2.57 per day) or $86 one-time (about $2.87 per day). You're paying for the strongest formula and research of the four, backed by a 90-day money-back guarantee, the longest of any brand here.⁷

Final Verdict: OMI Hair Growth Peptides Is the Clear Winner

After comparing OMI, Neutrogena, The Ordinary, and Vegamour, we found one winner with the most targeted formula, the strongest research, and a simple two-capsule routine. And that's OMI Hair Growth Peptides.

Ready to try OMI?

References

1. OMI Hair Growth Peptides ingredients at Violet Grey
2. Neutrogena Hair Restore Pro-Collagen Peptide Supplement
3. The Ordinary Multi-Peptide Serum for Hair Density at Sephora
4. Vegamour GRO Hair Serum
5. How denatured alcohol affects your skin, Healthline
6. Common causes of contact dermatitis, American Academy of Dermatology
7. OMI Hair Growth Peptides
8. OMI clinical trials
9. Cynatine HNS keratin study on hair and nails (2014)
10. keraGEN IV keratin study on hair, skin, and nails (2024)
11. The Ordinary Multi-Peptide Serum for Hair Density
12. Research review of Redensyl, Capixyl, and Procapil, Perfect Hair Health
13. Vegamour GRO Hair Serum reviews at Sephora
14. Neutrogena Hair Restore Pro-Collagen Peptide Drink Mix at H-E-B

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