Peptides for hair growth—what you need to know

Can peptides really help you grow thicker, healthier hair?

If you’ve spent any time in the haircare aisle—or scrolling on TikTok—you’ve probably seen the word peptides popping up. Once reserved for anti-aging skincare serums, these short chains of amino acids are now the latest promise in the battle against hair loss, breakage, and thinning.

But what are they really? In simple terms, peptides are tiny proteins that act like messengers, telling your body to kickstart essential functions, like making more collagen, elastin, or keratin. When it comes to your scalp and strands, that means stronger hair, better growth conditions, and potentially even reactivating dormant follicles. 

That said, not all peptides come in the same form, and not all of them actually do what they claim. From topical formulas to clinical-grade injectables, the world of peptide-based hair growth is wide, weird, and still evolving.

We’re cutting through the noise to explain how peptides work, which types are most promising, and how to use them wisely as part of a healthy hair routine.

 

So… what actually are peptides?

Peptides might sound like something out of a biology textbook, but they’re quickly becoming one of the most talked-about ingredients in hair care. Put simply, peptides are short chains of amino acids—the building blocks of protein—that send signals to your cells to perform specific functions. In skincare, that usually means boosting collagen. In haircare, it’s about strengthening strands and encouraging new growth.

Lately, peptides have made the leap from lab-based research to your shampoo bottle, with brands claiming everything from thicker hair to regrown edges. But does the science back it up? The short answer: it depends on the type of peptide, how it’s delivered, and what condition your scalp and follicles are in to begin with.

There are two main types making waves right now: topical peptides, found in serums and treatments you apply to the scalp, and injectable peptides, which are still largely used in clinical or medical settings. Both have shown promise, but not all formulas are created equal (more on that below).

Keep reading, as we’re unpacking what peptides can realistically do for hair growth, what’s worth trying, and how to pair them with a solid routine for the best results.

 

Peptides for hair growth—how do they work and which ones deliver?

Peptides are having a major moment in hair care, and we’re not surprised why. At their core, peptides are messenger molecules. Once applied (or injected), they send signals that encourage your body to produce the proteins hair needs to grow, namely keratin and collagen. Keratin makes up the bulk of your strands, while collagen supports scalp elasticity and overall follicle health.

That alone makes them worth exploring, but the benefits don’t stop there.

Some peptides boost scalp circulation, helping nutrients and oxygen reach the follicles more effectively. Others can extend the anagen phase (the active growth phase) of the hair cycle—essential for keeping hair growing longer, stronger, and fuller. And many have anti-inflammatory properties, which may help calm stressed-out scalps and reduce hair loss caused by inflammation.

So which peptides are actually worth knowing?

Copper peptides (GHK-Cu)

Arguably, the most studied in the context of hair growth. These support angiogenesis (new blood vessel formation) in the scalp and assist in regenerating tissue around the follicle. According to MDhair, a study found that using a copper peptide serum resulted in a 27% increase in hair density after six months of daily use.

Acetyl tetrapeptide-3

Often paired with red clover extract, this peptide has been linked to stronger anchoring proteins in the follicle and improved follicle size. Some evidence suggests it helps reduce hair fall and promotes the retention of existing strands.

Matrixyl (palmitoyl pentapeptide)

While more common in skincare for its collagen-boosting properties, it’s popping up in some hair products aimed at repairing scalp structure and encouraging regrowth.

Remember: Not all peptides are created equal, and not all studies are conclusive. Many of the clinical trials conducted so far are small in scale or limited in duration. But the results are promising enough that peptides have earned a place in the conversation around non-invasive hair regrowth.

What matters more than the peptide itself? The formula. 

Peptides need the right support system—think hydration, delivery systems, and synergistic ingredients—to actually make it to the scalp and do their job. For example, copper peptides are most effective in water-based formulas that maintain the correct pH and allow them to bind properly.

If you’re dealing with early-stage thinning, postpartum shedding, or just want to proactively support scalp health, peptide-based products can be a powerful tool. But as with any treatment, consistency and patience are key. Visible results may take a few months.

 

Topical peptides vs. injectable peptides

Peptides might be trending, but how you use them matters just as much as which ones you choose. Right now, there are two main ways to deliver peptides to the scalp: topically or via injection. Each comes with its own pros, cons, and considerations.

Topical peptides are the most accessible option 

Found in serums, scalp treatments, and even some shampoos, they’re designed for regular at-home use. These formulas typically work best when massaged directly into the scalp and left on, allowing the peptides time to absorb and signal the skin to produce strengthening proteins like collagen and keratin. 

While the effects can take a few weeks or months to show, they’re generally non-invasive, easy to incorporate into a routine, and suitable for early-stage hair concerns.

Injectable peptides, on the other hand, are more intensive

These are often administered in dermatology clinics or trichology centres as part of targeted hair restoration treatments. Delivered directly into the dermal layer, they can offer faster or more noticeable results, especially for more advanced hair thinning or loss. But they also come with a higher price tag, require professional oversight, and aren’t usually a first-line option for everyone.

The key takeaways? Topical peptides are great for building into your weekly routine, while injectables are better suited for clinical intervention. If you’re just starting out, topical products—with the right ingredients and consistency—can still do plenty of good.

 

What to look for in a peptide hair product

Heads up: Just seeing “peptide” on the label doesn’t guarantee results. To make sure your treatment is actually doing something, look beyond the buzzword and check the full ingredient list and formulation.

Here’s what to look for.

– Copper peptides or acetyl tetrapeptide-3 for stimulating hair growth and improving follicle health

– Niacinamide to boost circulation and support scalp barrier function

– Caffeine for energising follicles and potentially extending the growth phase

– Panthenol (pro-vitamin B5) to improve moisture retention and strand elasticity

– A lightweight, non-drying base—preferably water-based and free from drying alcohols or strong surfactants

– pH-balanced formulas that support absorption and scalp comfort

Peptides work best in synergy, not isolation. And a good formula should feel hydrating, not harsh. Plus, it should slot easily into your routine. 

Pro tip: If you're using a peptide scalp serum, pair it with a hydrating shampoo and conditioner to maintain moisture levels and support overall scalp health. Balanced care equals better results.

 

How to use peptides for hair growth in your routine

Peptides are most effective when they’re part of a consistent, balanced routine. The good news? They’re easy to integrate. Here’s a simple example:

1. Shampoo and condition as usual with a hydrating formula.

2. Apply a peptide serum to damp scalp (not soaking wet), focusing on areas of concern.

3. Massage gently for 1–2 minutes to aid absorption.

4. Style as normal—most topical peptides are leave-ins, so no need to rinse.

Some peptide treatments also come in rinse-out formulas (similar to conditioners). These are best used once or twice weekly, depending on hair type and product instructions.

How often?

2–3 times per week is a good starting point for most. If you’re using a stronger or clinic-prescribed product, follow professional guidance. Give it several months, MDhair advises, and you may see noticeable improvements in thickness, density, and reduced shedding.

What not to mix it with:

Avoid applying peptides right after strong exfoliants or treatments with high alcohol content, as these can interfere with absorption or irritate the scalp.

 

Potential side effects + safety

Peptides are generally safe for topical use, but as with any active ingredient, some people may experience sensitivities.

Common side effects can include:

– Mild scalp irritation or redness

– Itching or dryness (especially if overused)

– Breakouts near the hairline (in rare cases)

To minimize risk, do a patch test first, particularly if you have sensitive skin or scalp concerns. Avoid applying peptides to broken or inflamed skin.

If you're pregnant, breastfeeding, or undergoing treatment for a medical condition, consult your doctor before adding new actives to your routine.

Used correctly, peptides can be a low-risk, high-reward addition to your hair care plan, but always listen to your scalp and adjust as needed.

 

What peptides for hair growth can and can’t do

Peptides are a powerful tool, but they’re not a cure-all. Consider them as part of a bigger picture: regular trims, stress management, good nutrition, and hydrating hair products all work together to support healthier, fuller hair. Keep your expectations realistic and your routine consistent.

 

Small molecules, big potential

Peptides might be tiny, but their impact on hair health is anything but small. From strengthening strands to promoting growth, the right peptide treatments can support your hair goals, even more so when paired with consistent care and a nourishing routine. No matter if you're exploring topical serums or just getting familiar with ingredient labels, doing your research pays off.

Want more research-backed tips, product guides, and honest advice on building a better hair routine? Head over to the LifeTYME blog for an up-to-date dose of inspo.