The Signal Your Follicles Have Been Waiting For

Hair growth isn’t automatic; it’s guided by a complex and layered biological system. Learn about your hair growth cycle, factors that can trigger shedding and the role peptides play  in supporting and helping to create strong, full, resilient hair.

How Hair Growth Signals Influence Stronger, Healthier Hair

Most conversations about hair start with what we can actually see: shine, thickness, split ends, how it looks on a good hair day versus a bad one. But the real story begins within the follicle itself.

Hair growth is much more than cosmetic beyond what products you use. It’s biological. Every strand you see is the result of a complex process happening beneath your scalp, guided by signals your body and hair follicles are constantly sending and receiving. Understanding those signals is one of the most important (yet overlooked) keys to supporting healthy hair.

What’s Actually Controlling Your Hair Growth

At the root of every strand (literally) is the hair follicle, a small but incredibly active structure beneath your scalp. At the base of each hair follicle is the dermal papilla, a cluster of specialized cells that essentially act as the control center for hair growth. These cells direct the hair growth cycle, deciding whether your hair keeps growing or transitions towards shedding.[1] Nutrient levels, circulation, inflammation and overall cellular communication are all factors that play a role in your hair growth cycle.[2] In other words, your hair growth cycle isn’t automatic, it’s very specifically directed. 

Your Hair Is Always Cycling

Hair doesn’t just grow continuously, it moves through a repeating cycle of growth, transition and rest. The three stages of the cycle are: 

1. Anagen (Growth Phase)

During the anagen phase, your hair follicle is fully “on.” Cells in the root are rapidly dividing, pushing the hair shaft up and out of the scalp. At any given time, most of your hair (about 85-90%) is in the growth phase. This is the phase that determines the length, thickness and overall quality of your hair. What’s interesting is that this phase can last anywhere from two to seven years, which depends on genetics but is also influenced by nutrition, health and internal signaling. 

2. Catagen (Transition Phase)

After the growth phase, the hair doesn’t stop growing abruptly; it goes through a short transition period that lasts only a few weeks, but a lot happens during this time. The follicle begins to shrink and detach from its blood supply, essentially signaling that active growth is coming to an end. Cell division slows, and the hair is no longer being pushed upward at the same rate. It’s a kind of wind down period for the hair follicle as it prepares to move into rest mode. While the hair is still in place, it’s no longer actively growing. Only a small percentage of your hair is in this phase at any given time.

3. Telogen (Resting Phase)

This is when your hair takes a pause. During telogen, the follicle is inactive and the hair is essentially resting in place. There’s no new growth happening, but the hair hasn’t fallen out either. This period typically lasts two to three months. Eventually, the hair sheds, triggered by brushing, washing or even just moving around naturally. Simultaneously, a new hair is beginning to form underneath to start the cycle all over again.

It’s normal to lose 50 to 100 hairs daily as part of this shift. It can start to be concerning when more hairs than usual shift into this resting phase at once. That’s when you notice shedding or thinning; it often reflects something that happened weeks or months before, such as stress, an illness, or hormonal changes, that impacted the hair growth cycle.[3]

How Hair Growth Signals Come Into Play

Your hair follicles rely on biological signals to regulate how long hair grows, when it sheds and how strong each strand becomes. The health of your hair is largely determined by how well these internal signals are functioning. These signals are constantly being influenced by everything that’s happening inside your body (and factors that impact what’s happening in your body) including stress, nutrient intake, circulation, inflammation, cellular communication and metabolic changes. When signaling is strong and consistent, hair stays in the growth phase longer. When it’s disrupted or weakened, your hair follicles can prematurely shift into shedding mode.[4]

The Hidden Delay in Hair Shedding

One of the most misunderstood aspects of hair loss is timing. You might notice increased shedding and think it’s something recent, but in reality the change likely started weeks (even months) earlier. Hair shedding often occurs eight to 12 weeks after a biological shift. The lag is why the changes can feel sudden and confusing as to what the cause is. By the time you see it, the shift has already happened at the follicle level. 

Where Peptides Come In

Peptides are essentially short chains of amino acids that act like messengers in the body. They don’t build hair directly the way protein does, but they help guide the process. Peptides also carry hair growth signals that help coordinate cell turnover, tissue repair, your response to stress and how long hair stays in the growth phase. When it comes to hair biology, peptides also may help support communication within the follicle, help maintain the growth phase and support activity in the dermal papilla, connective tissue located at the base of the hair follicle which acts like a signaling center.[5] Peptides are less about forcing hair to grow and more about supporting and helping the system that drives hair growth function at its best. This is why peptides have become a focus in the recent and growing body of hair research.

Hair Growth Is a System, Not a Single Factor

It’s easy to think of healthy hair growth depending on one thing, but multiple systems working together are what’s responsible for strong, resilient hair. Your body needs the right materials to build strong hair. Your cells need the right instructions to set the process in motion. The follicles need a supportive, healthy environment to do their job, and the timing of the growth cycle has to stay balanced. When one part of the system is out of whack, the effects may not be immediate, but they show up over time.

The Future of Hair Growth: Where the Science is Headed

Hair research is really starting to reflect this more nuanced, layered, bigger-picture understanding of the hair growth cycle and the changes that can happen. Instead of focusing solely on external treatments, researchers are studying how to support the biological systems that regulate hair growth; factors like follicle signaling, cellular communication and aligning with natural growth cycles. It’s a shift towards a more precise, biology driven, inside-out approach to hair health 

The Takeaway

Hair growth starts way beneath the surface at the cellular level and it’s guided by signals your body is constantly sending. Hair growth isn’t automatic; it’s guided by biological systems. When those systems and signals are working well, hair tends to grow stronger, stay in its growth phase longer and shed less prematurely. It’s about supporting the system responsible for growing strong, healthy hair.

Frequently Asked Questions

Why does my hair seem like it’s suddenly shedding more than usual?

It may feel sudden, but hair shedding is usually a delayed response to changes that started happening weeks or months earlier, like stress, hormonal changes or an illness. By the time you notice the effects on your hair, the shifts have already taken place in the hair growth cycle.

Can I actually influence my hair growth cycle?

To a degree, yes. While genetics play a role, factors like stress, nutrition, circulation and overall scalp health can influence how long your hair stays in the growth phase and how well your follicles function. Supporting these internal systems can help create a better environment for healthy hair growth.

How do peptides fit into hair growth?

Peptides act as messengers that help support communication within the hair follicle. Rather than directly building hair, they help guide processes like cell turnover, growth phase maintenance and follicle activity. Think of peptides as supporting the system that controls hair growth.