Peptides for Hair Growth: What Are Peptides and How Do They Work?

If you spend any time on BeautyTok, you’ve probably seen your fair share of influencers gush about the benefits of peptides for hair growth. These ingredients are having a moment, thanks to their ability to promote thicker-looking strands and faster hair growth. But unless you’re deep in the beauty world, you might not be totally clear on what peptides actually are—or why they’re suddenly being treated like the next big thing in haircare.

In simple terms, peptides are short chains of amino acids that act like tiny messengers in the body, helping signal specific biological processes. In haircare, certain peptides are used to support strong, healthy strands, promote hair growth, and enhance volume and shine. The catch? How you use them—and what formulas you choose—really matters. Ahead, we’ll break down what hair growth peptides are, how they work, and what you need to know to use them properly for the best results.

What Are Peptides?

To understand peptides, it helps to start with what hair is actually made of. Your strands are primarily composed of keratin, a structural protein that gives hair its strength and shape. Your scalp, meanwhile, is rich in collagen, a protein that helps maintain your skin’s moisture and elasticity. When these proteins break down over time—due to heat styling, chemical treatments, or everyday wear and tear—your hair can start to become weaker, thinner, and more susceptible to damage.

That’s where peptides come in. According to the Cleveland Clinic, peptides are short chains of amino acids, the same building blocks that form proteins, including keratin and collagen. While there are countless different types of peptides used in the beauty industry, collagen peptides are among the most well-known. Proponents claim that haircare products with this ingredient can help support hair strength, boost density, and improve overall hair health.

How Do Peptides Support Hair Growth?

If you’re curious about adding peptides to your haircare routine, you may be interested in learning how, exactly, they work. Here’s a quick rundown of the different ways peptides may help support hair growth.

Strengthen hair fibers

Hair breakage usually starts when the hair’s outermost layer—the cuticle—becomes damaged. Once the cuticle is compromised, strands lose moisture more easily and start to feel rougher, drier, and weaker. Over time, that combination makes hair more prone to split ends and breakage. This is where collagen peptides may help. A 2024 study published in the Journal of Functional Foods found that treating hair with collagen peptides strengthened hair bonds, increased moisture, and smoothed the cuticle, which led to improved hair elasticity.

It’s important to note that the study didn’t show collagen peptides directly stimulate hair growth. Instead, by improving elasticity and helping hair retain moisture, collagen peptides may reduce breakage. In turn, that can support the look of a fuller, healthier mane by helping you hold on to the hair you already have.

Stimulate hair follicles

Copper peptides are among the best peptides for hair growth, thanks to their ability to stimulate the hair follicles. Research shows that copper peptides can help improve blood flow around the hair follicles and support the active growth phase of the hair growth cycle. Some research even shows that copper peptides can suppress a gene associated with premature hair loss. However, copper peptides are relatively unstable and don’t absorb well when applied topically, so their benefits are somewhat limited.

Protect against external stressors

Research shows that some peptides, including copper peptides, have antioxidant properties. Products with this peptide may help protect your hair and scalp against damaging free radicals, which helps to support a healthy scalp environment and minimize oxidative stress. By supporting a healthy scalp, copper peptides may help create the optimal environment for healthy hair growth.

What Are The Best Peptides for Hair Growth?

There are countless peptides used in the beauty industry, but a few stand out for their ability to support healthy hair. Below, we’re sharing a quick overview of some of the best peptides for strong, healthy-looking hair.

Copper peptides

Copper peptides are well-studied and shown to be a promising option for anyone looking to reduce hair loss, improve density, or support healthy hair growth. Because copper peptides don’t absorb well topically, however, actually incorporating them into your routine can be tricky. If you want to use copper peptides for hair growth, consider scheduling a chat with your dermatologist. Depending on your concerns and goals, they may recommend undergoing an in-office treatment, such as microneedling, before applying topical peptides to enhance absorption.

Collagen peptides

Collagen peptides can be used topically or taken orally, via a daily vitamin or supplement. Though research focusing on collagen peptide for hair growth is limited, evidence shows that collagen peptides—and collagen-infused haircare products—may help support thicker, stronger, and healthier-looking hair over time.

Keratin peptides

Keratin peptides are primarily used to help restore damaged hair, rather than stimulate hair growth. Research shows that products with keratin peptides may help to reinforce hair bonds, strengthen the hair, and improve resilience. This may make keratin-infused haircare products particularly beneficial for those with heat or chemically-damaged hair.

Keep in mind that this is by far from an exhaustive list. There are a nearly endless number of peptides, many of which—including biotinoyl tripeptide-1 and BPC-157—are emerging as possible hair-supporting compounds. However, research at this point is limited, and newer peptides can be difficult to find in haircare products. If you’re experiencing hair loss or thinning and think peptides may be right for you, consult a dermatologist or trichologist. They can help determine the underlying cause of your haircare concerns and recommend the best approach for your unique needs.

How Are Peptides Used in Haircare?

There are a few different ways that you can incorporate peptides into your haircare routine, and the best approach depends on your hair condition, needs, and goals. Here’s a brief overview of the most common ways to use peptides to support strong, healthy-looking strands.

Topical haircare products

The most accessible way to use peptides is with topical hair products, including shampoos, conditioners, leave-in serums, and scalp treatments. These formulas are designed to deliver peptides directly to the hair fiber and scalp, where they can help strengthen strands, support scalp health, and improve the overall look and feel of hair. Most peptide-infused shampoos and conditioners are gentle enough for daily use, while serums and treatments are often applied once or twice a day or a few times per week, depending on the formula.

When it comes to results, topical peptides typically require consistent use over several weeks to a few months. While you may notice smoother, softer hair sooner, improvements in strength, elasticity, and reduced breakage tend to build gradually with regular application.

Oral supplements

Peptides also appear in supplement form, most commonly as gummies or powders you can mix into your morning coffee. These are marketed to support hair, skin, and nail health from the inside out by providing amino acids the body uses to build proteins like keratin and collagen. Supplements are typically taken daily or weekly, depending on the product, so it’s important to follow label instructions carefully.

Like topical products, supplements aren’t an overnight fix. Most people need to take them consistently for at least 8 to 12 weeks before noticing visible changes in hair strength or fullness. And because supplements can interact with medications or underlying health conditions, it’s always a good idea to consult your doctor before adding any new supplement to your routine.

In-office treatments

Some dermatology and medical spas offer in-clinic peptide treatments, such as mesotherapy or injectable peptides for hair growth that are injected directly into the scalp. These procedures are intended to deliver concentrated active ingredients closer to the hair follicles and are usually performed less frequently than at-home treatments—often in a series of sessions spaced weeks apart, depending on your goals and needs.

Because these treatments are more intensive, results may appear sooner than with topical or oral products, but they’re not a guaranteed solution for hair loss. It’s important to consult a qualified medical professional to determine whether in-office peptide treatments are appropriate for you and to understand the potential risks and benefits.

Are Peptides Better Than Other Hair Growth Solutions?

A common question is whether peptides are “better” than established hair-loss treatments like minoxidil. The short answer: they do different things. Minoxidil is an FDA-approved medication that works by extending the growth phase of the hair cycle and increasing blood flow to the follicles, which can help stimulate new hair growth in people with certain types of hair loss. Peptides, on the other hand, aren’t drugs. They’re cosmetic ingredients designed to support the hair and scalp environment by helping signal follicles, strengthen existing strands, and improve scalp health.

Because of that difference, peptides aren’t a direct replacement for FDA-approved treatments. Instead, they’re better thought of as a supportive addition to a gentle, protective haircare routine (more on that ahead).

How To Promote Full, Healthy-Looking Hair

If you don’t want to take supplements or visit the dermatologist for in-office peptide treatments, that’s okay—there are plenty of other things that you can do to support a thick, healthy-looking mane. Read on for our top tips, plus a look at some of our favorite products for keeping your strands strong and resilient.

Use a hydrating shampoo and conditioner

One of the best ways to protect your hair from damage—and, in turn, breakage—is to ensure your everyday routine supports healthy-looking hair. To start, we recommend reaching for a gentle shampoo and conditioner that cleanse without stripping your hair of much-needed moisture. If your hair is thin and you’re looking for an added boost, try a volumizing system, like the L’Oréal Paris Elvive Hyaluron + Plump Hydrating Shampoo and L’Oréal Paris Elvive Hyaluron + Plump Hydrating Conditioner. This drugstore duo features hyaluronic acid and helps replump dry hair for up to 72 hours without any weigh down. Use the pair daily—or whenever you lather up—for shiny, bouncy strands.

Deep condition weekly

Once per week (or more often, depending on your hair’s condition) give your tresses some TLC with a deep conditioning mask. These formulas tend to be richer than your everyday conditioners and are often formulated with ingredients designed to help support hair strength, repair, and resilience. One option we love, particularly for those with brittle or fragile hair, is the L’Oréal Paris Elvive Total Repair 5 Damage-Erasing Mask. It’s enriched with a 17% repair concentrate with protein and helps target five key signs of damage, including split ends, roughness, and fragility. Apply the rich, balm-like formula to damp hair after shampooing, let it sit for up to five minutes, then rinse for soft, silky-feeling strands.

Color with care

Frequently coloring your hair—either at the salon or at home—can be damaging, especially if the process involves bleaching your strands. To help keep your hair looking and feeling its best, try to limit how often you dye or lighten your hair. When you do color your strands, use a gentle hair dye (ammonia-free options are great), opt for a darker hue if possible, and always follow up with a deep conditioner to help replenish moisture and protect your strands. If you need a recommendation, we love the L’Oréal Paris Superior Preference Shine Protect Ultra Care Conditioner.

Minimize heat styling

Heat can do a number on your hair—and the highter the temperature, the more likely your hair is to get damaged. To help prevent heat damage and breakage, try to limit how often you reach for the blow dryer, curling iron, or flatiron. When you do need to heat style your hair, be sure to prep it well with a heat protectant, such as the L’Oréal Paris EverPure Sulfate-Free Moisture 21-in-1 Leave-In Conditioner. The lightweight mist hydrates, smooths, boosts shine, and tames frizz—all while helping to shield hair from temperatures up to 450 degrees Fahrenheit. Spritz it onto damp strands, comb through, then style as usual for smooth, healthy-looking hair.

Don’t neglect your scalp

Healthy hair starts with a healthy scalp, and you can’t expect your hair to look its best if your scalp is overloaded with haircare products, sebum, or flakes. Once weekly, give your scalp a thorough (but gentle) deep clean with the L’Oréal Paris Elvive Hyaluron + Pure Oil-Erasing Serum. It’s made with hydrating hyaluronic acid and a 6% exfoliating complex with salicylic acid and gently removes all traces of impurities to leave the scalp feeling purified and refreshed for up to 72 hours. To use it, massage a generous amount onto your dry scalp for roughly five minutes, then let it sit for another 15 minutes. Once the time’s up, hop in the shower and lather up with your preferred shampoo and conditioner, then dry and style as usual.

Common Myths and Misconceptions About Peptides for Hair

Peptides are everywhere right now, which means there’s no shortage of hype—and a few misunderstandings—around what they can actually do for your hair. Here are some of the most common myths, plus the reality behind them.

• Myth: Peptides can regrow lost hair: Peptides aren’t a drug treatment for hair loss and haven’t been proven to regrow hair on their own. They’re best understood as supportive ingredients that help strengthen existing strands, improve scalp health, and optimize the environment around the hair follicle. That can help reduce breakage and improve the look of fullness, but it’s not the same as stimulating new hair growth.
• Myth: Peptides work overnight: Like most hair-care ingredients, peptides require consistent use over time. While you may notice smoother or softer hair within a few weeks, visible improvements in strength, elasticity, or reduced breakage typically take one to three months of regular use.
• Myth: All peptides are the same: There are countless types of peptides, and they’re used for different purposes in hair and skincare. Some are designed to support scalp health, others to reinforce the hair fiber, and others to signal biological processes. The effectiveness of a peptide product depends heavily on the specific peptides used, the formula, and how consistently you apply it.
• Myth: Peptides can replace FDA-approved hair-loss treatments: Peptides aren’t a substitute for evidence-based treatments like minoxidil. While they can complement a routine and help support healthier-looking hair, they’re not a replacement for clinically-proven hair loss treatments.
• Myth: Peptides only work if you take them as supplements: Peptides can be used topically, in-office, or as supplements, and each format works differently. Topical products act directly on the scalp and hair fiber, while supplements provide amino acids the body uses to build proteins like keratin and collagen. No single format is inherently “better”—it depends on your routine, goals, and hair concerns.

Next Up: Hair Treatment for Thin Hair: How To Care for Fine Strands

Photo courtesy of L’Oréal Paris