Hot Girl Science: Your Hair Has a Growth Cycle, Your Supplements Should Have One Too

This is the surprising science behind shedding, stress, DHT, and why your hair might need more than a biotin gummy. How many products do you have for your hair? There’s a shampoo for volume, and another for repair. A leave-in conditioner, a scalp treatment, a hair mask, some oil that is too cool to even have a name so it’s just a jumble of numbers and letters or symbols like the artist formerly known as Prince. 

Don’t forget your superhero heat-shield spray that protects your hair from that evil hair dryer. You even bought some very expensive gummies after you fell for a slow-motion hair flip online. The problem here is that your hair is superbly complicated. It’s cycling, growing, resting, shedding, and starting the process all over again. Researchers have spent decades figuring out what makes that cycle speed up, slow down, or occasionally go completely off the rails. After a ton of research, we created Hair + Beauty Vitality Capsules to bring together all of nature’s powerhouse players to support the full cycle in all its many moods and phases, along with some bonus features for your nails and your skin. Let’s break it down.

We start with shedding. There are two types. The normal kind, where you find a few hairs in the shower, shrug, and get on with the towel-dry. Then, there’s the kind when you clean your hairbrush and wonder how good you look in hats. If your shower drain is starting to look like a small animal has curled up and died there, it might be time to take action. 

The whole shedding issue is quite common, and there are a lot of reasons it can happen. Let’s throw a bit of stress, illness, nutritional issues, hormonal changes, genetics, and even your biology onto the fire. Your hair follicles won’t start producing strands just because you asked nicely. Basically speaking, your follicles have a calendar, and they don’t care a bit about your big date or your vacation plans. 

Every hair follicle cycles through different phases. Let’s break them down. 

Introducing anagen, the active growth phase. 

Next comes catagen, a short transitional phase. 

Then telogen comes knocking on your door, the resting phase.

Eventually, the old hair is released and the follicle gets ready to start the whole ridiculous song and dance of a process all over again. Researchers also describe an exogen phase associated with shedding.

To recap, that’s ⇢ grow ⇢ transition ⇢ rest ⇢ shed ⇢ repeat. Your follicles are basically running a tiny production facility 24/7. The important part is that things can influence which phase a follicle spends its time in. Inflammation, hormones, stress, nutritional deficiencies, poor sleep, and certain medications have all been discussed as factors that can influence the hair cycle. So this is where things get interesting. Sometimes the problem isn’t that you're having a bad hair day. Your follicles may simply have received a series of biological signals telling them to take a little break.

One particularly common type of diffuse shedding is telogen effluvium. The name sounds like something an evil doctor would say while wearing a lab coat and staring intensely into a microscope. It basically describes excessive shedding associated with a greater number of hairs entering the resting phase. 

Physiological stressors such as childbirth, illness, sudden weight loss and other significant changes can trigger it. Stress is considered an important contributor, although the condition is multifactorial and figuring out the exact cause can be complicated. Which brings us to one of the more annoying facts about being a woman. Your hair has opinions about your life. 

When you have a bad night’s sleep, your follicles may notice. You're going through some major stress; they may notice that too. You decide to go on a crash diet, and your hair is going to get very pissed off. This doesn’t mean every stressful Monday sends hundreds of hairs into early retirement. Biology is considerably more complicated than that. It does mean that supporting healthy hair isn’t necessarily about one magical growth ingredient. Often, it’s about looking at the bigger picture.

Now for the hormone nobody invited that gets blamed for everything. Dihydrotestosterone, or DHT, is an androgen made from testosterone by the enzyme 5-alpha-reductase. It has a well-established role in male androgenic hair loss. Women, however, are not simply prettier men with better handbags. The relationship between androgens and female pattern hair loss is considerably more complex. 

A 2025 clinical review notes that DHT plays a crucial role in male androgenetic alopecia, but its exact role in female pattern hair loss remains unclear. If you don’t already know, female pattern hair loss can involve shortened growth phases and follicle miniaturization, but women don’t necessarily have the elevated androgen levels. 

DHT is not necessarily the mastermind villain behind your hair loss. DHT and androgen signaling are absolutely interesting areas of hair research, which is why ingredients that have been studied in this space have earned a place in some of those super hair-support formulas. This brings us to a botanical that has been hanging around eavesdropping on this conversation for quite some time.

It sounds like one of those ingredients that should be chilling in a Florida garden, but saw palmetto is quite an interesting player in the world of hair research. Compounds in the plant may influence 5-alpha-reductase, that enzyme involved in converting testosterone to DHT. Researchers have very much put this plant to the test. 

In a 16-week randomized, placebo-controlled study, a standardized oral saw palmetto oil preparation was associated with up to 29% reductions in hair fall compared with the baseline. Before you start screaming Rapunzel, Rapunzel, let’s break that down a bit more. 

That was a specific standardized saw palmetto preparation, in a specific study, lasting over 16 weeks. It doesn’t mean every saw palmetto supplement produces the same result, and it certainly doesn’t establish a guaranteed outcome for every woman. It does reveal something useful: saw palmetto isn’t just a decorative addition to the ingredient label. It has biological reasons for being there.

We did not make this name up. Spermidine is a naturally occurring polyamine involved in cellular processes, and researchers have become interested in what it might do for the hair-growth cycle. One randomized, double-blind, placebo-controlled human study gave healthy men and women a spermidine-based nutritional supplement or placebo for 90 days. 

The researchers looked specifically at hair follicles and found that the spermidine supplement increased the number of follicles in the active anagen growth phase. Researchers were looking to support the phase when the follicle is actually growing. Spermidine is included in Hair + Beauty Vitality Capsules because it brings that hair-cycle angle to the formula. Frankly, we can get behind any ingredient that can make the phrase “hair follicle proliferation” sound sexy.

Saying the name immediately relaxes you, which is a good thing because stress has been associated with telogen effluvium, and ashwagandha has been known to help reduce stress. We can’t just connect the dots and say it reduces stress, therefore ashwagandha grows hair. That’s not how science works. (It would be nice, though.) 

We are very interested in the connection between those two things. Ashwagandha has been studied in randomized controlled trials for stress and anxiety. A 2024 systematic review and meta-analysis covering nine randomized trials found significant improvements in measures including perceived stress, anxiety, and cortisol compared with the placebo. 

Our rationale for including it in these capsules: supporting a healthy stress response as part of a formula designed around the many factors involved in healthy-looking hair. Your follicles don’t need a spa retreat or a motivational speech. What they need is a supportive environment.

Ahhh, biotin. It’s the celebrity of the hair-vitamin world. The wellness world slaps biotin on a bottle and thinks every woman with a ponytail will become interested. To be fair, biotin is an important nutrient, but only in the right amounts. Like red wine, more is not automatically better. 

A 2024 review examining the evidence for biotin and hair loss found only three eligible studies and concluded that high-quality evidence doesn’t support biotin supplementation as a general hair-growth solution in healthy people, only when an actual deficiency or specific underlying condition is present. 

Then there’s another little detail the mega-biotin crowd coincidentally forgets to mention. High doses of biotin can interfere with certain lab tests and potentially produce incorrect results. This is why we don’t feel the need to turn our supplements into a biotin flex. Yes, Hair + Beauty Vitality Capsules include biotin, but it’s just one piece of the formula, not the entire personality.

It sounds like something you encounter in an enchanted forest, but it’s a real botanical that has traditionally been used in wellness and beauty preparations, and it contains silica-related compounds that have made it popular in hair and nail formulas. The interesting distinction here is between plausible nutritional support and proven hair-growth treatment. 

We won’t lie to you and say that horsetail is going to make your ponytail triple in size, but we will say it contributes silica to a formula designed to support the strength and appearance of hair and nails. Sometimes an ingredient’s job is simply to be a good team player. Not everybody can be or needs to be a Beyoncé.

Vitamin A has a serious résumé. This fat-soluble vitamin is involved in normal skin and hair biology, and its active metabolites interact with pathways involved in hair-follicle stem cells and the hair cycle. Please note, vitamin A is another ingredient where more is definitely not better. Both insufficient and excessive vitamin A can have undesirable effects, which is why sensible dosing matters.

Is this becoming a theme? Mega-dose everything is not the answer. Give us ingredients at clinically effective doses that make physiological sense so everyone can do their assigned jobs.

We’ve now reached curcumin, the compound responsible for all the research interest into turmeric. Curcumin has been studied for antioxidant and anti-inflammatory effects, including in dermatological research. A systematic review of clinical studies found evidence that Curcuma species and curcumin can influence inflammatory and antioxidant processes in the skin. A separate meta-analysis of randomized controlled trials found that curcumin supplementation reduced several markers associated with inflammation and oxidative stress.

Why does any of that matter in a beauty formula? Because scalp health isn’t just some cute phrase invented by a shampoo company. The scalp is skin. Hair follicles live in it. The biology happening around those follicles matters. Curcumin brings another piece to the puzzle, the antioxidant and inflammatory-pathway support.

We now arrive at our final ingredient, black pepper extract. It acts as the supporting character who makes sure all of the other ingredients can get absorbed. Curcumin? Notorious bandit with low oral bioavailability, which is one reason researchers have investigated combining it with piperine from black pepper. Reviews of human studies suggest piperine can increase curcumin bioavailability. So no, it’s not there to spice up the capsule; it’s there to make sure you get the most from every other ingredient.

Let’s zoom out and look back. Your hair doesn’t have one problem. It’s got an entire board meeting to discuss the issues. These include hair-cycle biology, hormonal signaling, stress, inflammatory pathways, nutrients, breakage, and scalp health. That’s without bringing in the fact you have to wash it, style it, blow-dry it, put it in ponytails, sleep on it, brush it, color it, occasionally attack it with a straightener or curling iron (dealer’s choice), and at the end emerge looking like a model from a shampoo commercial. 

Your follicles deserve overtime pay. That’s why we took a multi-prong attack within the multi-ingredient approach of our Hair + Beauty Vitality Capsules. We brought in saw palmetto to deal with the DHT/androgen aspects, spermidine to handle the hair-cycle issues, ashwagandha to help cope with stress, and the biotin to support normal nutrient metabolism (in an appropriate amount). Then horsetail brings its silica, curcumin carries in the antioxidant and inflammatory pathway support, and vitamin A boosts your skin’s and hair’s normal biology. Lastly, in comes the black pepper extract to ensure the bioavailability of the botanical compounds is at its peak. Our ingredients are team players.

If your current hair strategy is simply shampoo ⇢ conditioner ⇢ prayer ⇢ stare at the shower drain, it might be time for a bit of an upgrade. We created Hair + Beauty Vitality Capsules for women who want to support scalp health for stronger, shinier hair; hair-cycle and follicle support; reduced shedding and breakage for visibly fuller-looking hair; with the added bonus of skin, nails, and collagen-promoting nutrition. All of that arrives in two capsules a day, because here at Vital Source Nutrition we firmly believe your wellness routine should not require a spreadsheet to stay on top of.