The 5 Best Peptide Products for Longer, Thicker Hair

• Provides relatively quick results

• Can feel greasy if overapplied

This watery serum is meant to be applied and left on your scalp to work its magic. Thanks to peptides, caffeine, and various plant-based extracts, it not only densifies and thickens your hair but also helps your mane appear more voluminous overall.

Key ingredients: Peptides, caffeine, Redensyl, Procapil, Baicapil

Size: 1 oz.

Ulta rating: 4.1/5 stars

An ELLE editor says: “I don’t remember how I discovered this product, but I’m forever grateful I did. During the first two years of the pandemic, I applied the formula religiously every night, and I credit it for nursing my scalp and hair back to health after shocking and noticeable hair loss. I was amazed by the volume it provided (especially when I apply it while my hair is still damp from a shower) and how many baby hairs sprouted all over my head in the few weeks after I started using it.” —Carol Lee, ELLE.com associate beauty e-commerce writer

• Works for all hair types
• Lovely scent

• May not be suitable for dry hair

Hair care starts in the shower, and you can set your strands up for success by utilizing this shampoo and conditioner to cleanse and revitalize your hair and scalp. Rosemary oil is known for encouraging blood circulation in the scalp (which encourages healthy hair growth), and the addition of peptides and plant proteins translates to stronger, less breakage-prone locks.

Key ingredients: Rosemary oil, peptides, ceramides, proteins

Size: 8.4 fl. oz. x2

Necessaire rating: 4.5/5 stars

An ELLE editor says: “First of all, the scent of this duo is incredible—if you like rosemary, treating yourself to this is a must. I’ve gotten multiple compliments on how good my hair smells when I use this, and it’s currently in my rotation of shower products. Additionally, I’ve been applying a lot of heat to my hair these days, and my hair has maintained its strength and health—I don’t doubt that using these products has something to do with it.” —Carol Lee

• Clinically tested

• Some may dislike taste of collagen powder

Nutrafol is one of those hair growth supplements that actually work. “I used to get highlights, and my hair incurred a ton of damage. It got to the point where I didn’t feel like my hair could grow any longer than my shoulders. I tried Nutrafol supplements as a sort of last-ditch effort, and I couldn’t believe how quickly my hair started growing—and how healthy it looked,” says ELLE beauty editor Katie Berohn. This set also includes the brand’s collagen powder, which features marine collagen peptides to provide hydration and other materials for strong, healthy hair.

Key ingredients: Marine collagen peptides, saw palmetto, tocotrienol complex, ashwagandha

Size: 120 capsules and 12.03 oz. of powder

Amazon rating: 4.4/5 stars

An Amazon reviewer says: “This product really works! My hairdresser (without knowing I was taking anything) commented that my hair was growing and filling out more. I was thrilled!”

• A little goes a long way

• Small size

K18’s hair oil features the brand’s signature peptide, an ingredient that strengthens strands and makes them appear smoother. By preventing and repairing damage, the silicone-free oil allows your hair to grow without breaking off before it can reach your desired length.

Key ingredients: Peptides, hemisqualane, squalane, avocado oil

Size: 1 fl. oz.

Amazon rating: 4.4/5 stars

An Amazon reviewer says: “This stuff has helped my damaged, broken off hair so much. My hair was ruined with bleach, and this has been such a game changer in my hair journey. While it doesn’t help with growth, it helps repair the damaged hair. 10/10. Will purchase again!”

• Suitable for all hair types

• May take time to see results

You may already drink caffeine to wake you up in the morning, but when applied topically, the ingredient can also wake the scalp and make your hair feel and appear denser. Other starring ingredients include peptides to promote the health of hair follicles and grape stem cells to thicken hair.

Key ingredients: Grape stem cells, peptides, caffeine

Size: 3 oz.

Act + Acre rating: 4.8/5 stars

An Act + Acre reviewer says: “I tried this after seeing this on social media and reading the reviews. I have fine hair and breakage in one section. This has helped with the breakage and gives my hair volume at the scalp. As a bonus, I don’t have frizz or flyaways on the small hairs around my hairline.”

The best way to go about treating hair loss is to figure out the root of the problem. “It is important to identify and address what's leading to hair loss. For example, vitamin deficiencies can cause hair loss. Treating vitamin deficiency can encourage hair growth,” Dr. Spann says. She also recommends scalp oiling and scalp massage to promote hair growth.

According to Dr. Spann, it all depends on what kind of hair loss you’re dealing with. “Something like alopecia areata, a non-scarring, autoimmune type of hair loss, can be completely reversed. Female pattern hair loss can be reversed if the follicles are treated early before follicles become scarred,” she says. However, follicles that are already scarred are unable to recover.

As a leading publisher of fashion, lifestyle, and beauty content, ELLE.com is committed to highlighting the best products in various categories by personally testing the latest and most innovative products, interviewing countless experts, and vetting customer-loved items. For this piece, beauty writer Carol Lee spoke to a dermatologist, tested formulas, and combed through customer reviews to find the best peptide products for hair growth.