Hair Loss in Men: Why It Happens (and What Actually Works)
Quick answer
The most common cause of progressive hair thinning in men is androgenetic alopecia, better known as male pattern hair loss. Certain follicles are genetically sensitive to androgens, particularly DHT, and gradually miniaturise over time. But not every bit of shedding is male pattern hair loss: telogen effluvium, nutritional deficiencies, some medical conditions and certain medicines can also trigger hair loss. If the pattern points to androgenetic alopecia, starting early matters. Medical treatments such as minoxidil and 5-alpha-reductase inhibitors are among the options with the strongest evidence. Cosmetic scalp care and nutritional support can complement that strategy, but they do not replace a diagnosis or medical treatment when one is needed.
If you have been spotting more hair in the shower, your hairline seems to be creeping back or your crown is suddenly getting a bit too much screen time in overhead-light photos, you have two options: panic or work out what is actually going on. We recommend the second.
That is exactly what this guide is for: the main types of hair loss, how to tell them apart, what genuinely has evidence behind it and where a proper hair-care routine fits in. No miracles, no promises of a brand-new mane in twelve days, and no pretending every ingredient is a NASA breakthrough.
- How much hair is normal to lose each day?
- Main causes of hair loss in men
- Androgenetic alopecia or telogen effluvium: how to tell the difference
- What actually works for hair loss
- The actives under the microscope: what is in them and what the studies show
- Hair-loss myths
- A step-by-step hair-loss routine
- When to see a dermatologist
- Frequently asked questions
- Sources and evidence
How much hair is normal to lose each day?
As a general benchmark, losing around 50 to 100 hairs a day can be part of the normal hair cycle. Hair is not static: it moves through a growth phase (anagen), a transition phase (catagen) and a resting/shedding phase (telogen).
More useful than counting every single hair — what a thrilling hobby — is looking for a change from your own normal. If, for several weeks, you notice noticeably more shedding, lower density, a receding hairline or an increasingly visible crown, it is worth keeping an eye on the pattern and getting it checked if it continues.
One tip that is genuinely useful: take photos every 2-3 months using the same lighting, distance and angle. The mirror is pretty useless at spotting slow change. Two comparable photos are not.
Main causes of hair loss in men
1. Androgenetic alopecia: genetics + sensitivity to DHT
This is the most common cause of male pattern hair loss. It does not necessarily mean you have “too much testosterone” or that your DHT is “through the roof”. The key is that some follicles are genetically predisposed to respond to androgens, particularly dihydrotestosterone (DHT).
Over time, those follicles miniaturise and produce hairs that are progressively finer, shorter and less visible. It commonly starts around the temples, frontal hairline and crown and progresses gradually. That is why spotting it early helps: preserving a follicle that is still producing hair usually gives you more room to work with than trying to recover an area that has been severely affected for years.
2. Telogen effluvium: when suddenly much more hair starts falling out
A period of physical or emotional stress, fever, surgery, significant weight loss or a very restrictive diet can disrupt the hair cycle and cause diffuse shedding. The confusing bit is that the increased shedding often appears weeks or even months after the trigger, rather than while it is actually happening.
In many cases it improves once the underlying trigger is resolved, although heavy shedding, shedding that lasts for several months or hair loss with no obvious cause is worth getting assessed.
3. Diet, deficiencies and crash diets
Not eating enough energy or protein, as well as certain genuine deficiencies — iron deficiency, for example — can affect the hair cycle. But there is an important caveat: taking supplements “just in case” does not guarantee more hair. Biotin, for instance, is needed for the maintenance of normal hair, but deficiency is uncommon in healthy people eating a normal diet.
4. Seasonal changes
Seasonal variations in the hair cycle have been described, and some people notice more shedding in late summer or autumn. That does not mean every September shed is automatically “seasonal hair loss”. If density is progressively falling, there is a clear pattern around the temples or crown, or the issue sticks around, do not blame the calendar for everything.
5. Scalp problems
Severe dandruff, seborrhoeic dermatitis, inflammation, itching or excess oil are not the same thing as androgenetic alopecia. They can, however, leave the scalp in worse condition, increase discomfort and make a hair-care routine harder to manage. Sebum and DHT are not the same thing: keeping the scalp clean and balanced is sensible, but it is not a substitute for treating hair loss.
6. Medicines and other medical causes
Thyroid disorders, autoimmune diseases, some medicines and other medical conditions can also cause hair loss. If you develop round bald patches, sudden shedding, pain, crusting, severe inflammation or hair loss elsewhere on the body, this is not the time for DIY experiments. Get it checked.
Androgenetic alopecia or telogen effluvium: how to tell the difference
| Androgenetic alopecia | Telogen effluvium | |
|---|---|---|
| Distribution | Usually affects the temples, frontal hairline and crown | Usually causes diffuse shedding across the whole scalp |
| Onset | Slow and progressive | More sudden and noticeable |
| New hair | May become progressively finer because of miniaturisation | The main issue is increased shedding rather than a typical miniaturisation pattern |
| Trigger | Genetic predisposition and androgen response | Can follow stress, illness, surgery, weight loss or a restrictive diet |
| Progression | Tends to progress if left untreated | Often improves once the trigger is resolved |
What if both columns sound familiar? That can happen too. Telogen effluvium can overlap with androgenetic alopecia that was already developing in the background. The table is a guide; it does not diagnose you. That is what a proper examination — and trichoscopy when appropriate — is for.
What actually works for hair loss
The smartest approach is layered — with evidence behind it — and tackles the problem from three angles: the environment (the scalp), the cause (DHT) and the follicle’s energy supply. From lower to higher intervention:
Layer 1 — Smarter scalp care
Washing your hair every day does not make it fall out more (the hairs you see in the shower were already loose). A treatment shampoo with studied actives can support the follicle in three ways: nourishment (peptides and plant amino acids), microcirculation support (ginseng, red onion, niacinamide) and oil control linked to DHT pathways (Zinc PCA). That is exactly the thinking behind Hairicane, our strengthening and densifying shampoo, which contains its anti-hair-loss botanical complex at 3% — the shampoo dose used in the complex’s in vivo study. You can see the numbers further down.
Layer 2 — Consistent topical treatment
Topical hair-loss treatments applied directly to the scalp are the next step up: targeted actives designed to support the areas where miniaturisation is happening. The key word is consistency. Hair follicles work in cycles measured in months, so any topical needs at least 3-6 months of daily use before you can judge it properly. This is where Follicool, our intensive anti-hair-loss spray serum, comes in. It is not “a serum with one active”; it is a multi-complex formula: 5% Capixyl™ (the same concentration used in its clinical study — while half the industry name-drops actives at a fraction of the studied dose), the botanical complex at 10% (the treatment dose used in the in vivo study), glycogen, caffeine, green tea and topical saw palmetto. Plus menthol for that fresh hit: yes, you can actually feel it.
Layer 3 — Support from within
A well-formulated hair supplement can work in two ways. The first is nutritional: if the follicle is short on fuel, correcting that can show in the hair. The second is functional: botanical extracts such as Saw Palmetto have been studied for their ability to inhibit the conversion of testosterone into DHT — in other words, targeting from the inside the same pathway a topical routine works on from the outside. That is the logic behind Growzilla, our hair supplement for men: a formula that covers the nutritional side (biotin, zinc and further follicle support) as well as the functional side, led by Saw Palmetto. Same honesty as always: a supplement does not replace a topical. It adds support from within while the topical gets on with the outside job.
Layer 4 — Medical treatment
For established androgenetic alopecia, there are also pharmacological treatments backed by solid evidence. They are medicines, not cosmetics: they have indications and potential side effects, which is why they should always be assessed, prescribed and monitored by a doctor, who can look at your specific case and tell you whether the trade-off makes sense for you. What we can say here is that if you do take that step, the previous layers do not suddenly become pointless — looking after the scalp and supporting the follicle can still play a complementary role alongside whatever medical approach is chosen.
The actives, under the microscope
At Siwon, we like you to know what you are putting on your head, why it is there and what the studies actually found:
5% Capixyl™ — the intensive complex in Follicool
Capixyl™ is a biotechnology complex combining a biomimetic peptide (acetyl tetrapeptide-3) with red clover extract. It targets several pathways relevant to androgenetic alopecia at once: modulating DHT through 5-alpha-reductase inhibition, stimulating synthesis of the anchoring proteins that help secure the hair within the follicle, helping preserve follicular stem cells (the cells involved in producing new hair), reducing pro-inflammatory cytokines and helping rebalance the scalp microbiota. In its 4-month placebo-controlled clinical study, researchers measured +13% hair in the growth phase and −29% hair in the shedding phase — a clear shift in the growth/shedding ratio. Follicool contains it at 5%, the same concentration used in the trial. Tolerance-wise, it also scored well: tested as non-irritating, non-sensitising and non-phototoxic at the use level.
The anti-hair-loss botanical complex — shared by Hairicane and Follicool
Its key actives include hydrolysed soy protein (with an amino-acid profile remarkably similar to hair keratin), red onion extract, ginseng, Zinc PCA — which inhibits 5-alpha-reductase activity in the skin — niacinamide and biotin. Its in vivo study was carried out in men with androgenetic alopecia using a protocol of 3% shampoo + 10% treatment — exactly how we dose it: 3% in Hairicane and 10% in Follicool. The routine mirrors the studied protocol. That is not an accident. Results after 28 days: +10.2% hair count +10.9% hair density +13.1% growth/shedding ratio, plus a 26% increase in keratin synthesis measured in vitro.
Marine glycogen — fuel for the follicle
The follicle burns glycogen at twice the rate during the growth phase, and this ingredient (found in Hairicane and Follicool) helps replenish that supply, with epigenetic activity studied for its role in stimulating follicle growth. In its study, after 8 weeks of use in men with weak, fine hair, 70% of volunteers recorded a +19.3% increase in hair thickness and a −47% reduction in very fine hairs. Nutrition, circulation, energy and oil control: the full growing environment.
Saw Palmetto — anti-DHT support from two angles
Saw Palmetto (Serenoa repens) is probably one of the most studied botanical extracts in male hair health. Its proposed mechanism goes straight to the pathway: inhibiting the two isoenzymes of 5-alpha-reductase, reducing the conversion of testosterone into DHT — without altering blood hormone levels, which is one of the ways it differs from pharmaceutical treatments. In our routine, it works from two directions: orally in Growzilla — alongside biotin, zinc and the rest of the nutritional follicle support — and topically in Follicool, together with green tea, another mild inhibitor of the enzyme. Oral efficacy has been put to the proper test: in a double-blind, randomised, placebo-controlled trial in men aged 23 to 64 with mild or moderate androgenetic alopecia, it showed an average efficacy of around 60% of participants. It requires consistency (at least 4-6 months) and is generally well tolerated; if you take anticoagulants, speak to your doctor first.
The results quoted come from studies of the active complexes carried out by their developers under the conditions of each study. Different formulas and different people may produce different results — which is exactly why we keep banging on about taking a progress photo every three months.
A doctor's take
Dr Marcel Guiu Ortín (@marcelguiu) reviewed this guide. In this video, he explains some of the key points behind male hair loss and how to approach it sensibly without muddling together cosmetics, supplements and medical treatment.
Hair-loss myths we can finally retire
“My cap is making me go bald”
No. A normal cap does not cause androgenetic alopecia. If it is filthy, tight enough to double as a hydraulic press or irritating your scalp, you may have other problems. But it is not rewriting your genetics.
“If I shave my head, it’ll grow back thicker”
Nope. Cutting the hair shaft can make freshly cut hair feel thicker, but it does not change the follicle or alter its growth cycle.
“Washing it too much makes it fall out”
Washing can dislodge hairs that were already in the shedding phase. It does not create alopecia. If you have an oily scalp, washing less purely to “save your hair” is usually a pretty questionable strategy.
“More biotin = more hair”
It does not work like that. Biotin is important for the maintenance of normal hair, but taking more of it does not magically turn a miniaturised follicle into a brand-new one.
“Rosemary/onion/random oil means I don’t need anything else”
Some natural ingredients have research behind them and others have considerably less. The problem starts when an early signal gets treated as if it were equivalent to a diagnosis or to treatments backed by far stronger evidence. Less hair folklore. More knowing what type of hair loss you actually have.
Your anti-hair-loss routine, step by step
- Wash smart. Use a treatment shampoo daily or every other day, massaging the scalp for 60-90 seconds with your fingertips — not your nails — to support microcirculation and leave the scalp clean and conditioned. Botanical complex at 3% in the shampoo + 10% in the serum: the same protocol used in the in vivo study.
- Use your topical every day. On dry or towel-dried hair, apply the treatment directly to the scalp in the areas you are watching most closely (temples, crown), then spread it with a quick massage. Night after night, no negotiations: these actives work over hair cycles measured in months.
- Support it from within. Get enough protein in your diet, and consider nutritional support with Saw Palmetto if you also want to target the DHT pathway from within or you are coming out of a period of stress or aggressive dieting.
- Take a progress photo every 3 months. Same light, same angles (overhead and front). It is the most objective way to see whether you are moving in the right direction. The daily mirror lies; the quarterly photo is far less dramatic.
- Step things up if needed. If the six-month photo is still going backwards, see a dermatologist to discuss pharmacological options. The cosmetic layers can stay in place: they complement rather than compete.
The Siwon hair squad
22.99 €
Hairicane
Strengthening and densifying shampoo. A better scalp environment, every shower.
- 3% botanical complex: the shampoo dose used in its in vivo study
- Tested in men with alopecia: +10.9% density*
- Zinc PCA for oil control + 19 phytoactives
45.99 €
Follicool
Intensive anti-hair-loss spray serum. Straight to the scalp, 30 seconds a day.
- 5% Capixyl™: +13% hair in the growth phase in its trial*
- 10% botanical complex: the treatment dose used in the study
- Caffeine, green tea and topical Saw Palmetto for DHT-pathway support
34.99 €
Growzilla
Dual-action hair supplement: nutritional follicle support plus the DHT pathway from within.
- Saw Palmetto: studied in a double-blind trial
- Biotin, zinc and further nutritional support for the follicle
- 60 capsules = 1 month (2 a day)
*Results from studies of the active complexes under the conditions of each study. Full details in “The actives, under the microscope”.
When to see a dermatologist
Some situations are not worth waiting out: sudden or very heavy shedding, round bald patches, pain, severe itching, crusting, inflammation, loss of eyebrow or beard hair, or any other symptoms that appear alongside the hair loss.
And if the pattern looks clearly androgenetic — progressive thinning at the temples or crown — you can also see a dermatologist from the start. They can assess the pattern through examination and trichoscopy, decide whether blood tests are appropriate and talk you through medical treatments where relevant.
Frequently asked questions about hair loss
How many hairs is it normal to lose each day?
Around 50 to 100 hairs a day can fall within the normal hair cycle. Pay attention if the amount clearly increases for several weeks, if you are visibly losing density at the temples or crown, or if new hairs are coming through progressively finer.
How do I know if I have androgenetic alopecia?
It usually progresses slowly and follows a recognisable pattern around the temples, frontal hairline and crown. Hair in those areas may become progressively finer. A dermatological assessment and trichoscopy can confirm whether follicular miniaturisation is present.
Is autumn hair shedding normal?
Seasonal variations in the hair cycle have been described, and some people notice more shedding in late summer or autumn. If the loss is progressive, localised or persistent, it is best not to assume it is purely seasonal.
Can an anti-hair-loss shampoo stop alopecia?
A shampoo cannot reverse alopecia on its own, but well-dosed active complexes can show measurable results: in the in vivo study of Hairicane’s botanical complex, men with androgenetic alopecia recorded improvements in hair count, density and the growth/shedding ratio after 28 days. Think of shampoo as the foundation of the routine, not the whole treatment.
What is Capixyl™ and what evidence is there?
Capixyl™ is a biotechnology complex combining the peptide acetyl tetrapeptide-3 with red clover extract. It inhibits the enzyme involved in converting testosterone to DHT, supports hair anchoring within the follicle and helps preserve follicular stem cells. In its 4-month placebo-controlled clinical study, it showed +13% hair in the growth phase and −29% in the shedding phase. Follicool contains it at 5%, the concentration used in the study.
Does Saw Palmetto help with hair loss?
Saw Palmetto (Serenoa repens) inhibits the two isoenzymes of 5-alpha-reductase, reducing the conversion of testosterone into DHT without altering blood hormone levels. In a double-blind, placebo-controlled trial in men with mild to moderate androgenetic alopecia, it showed an average efficacy of around 60% of participants and was well tolerated. Consistency for at least 4-6 months is required.
How long does a hair-loss treatment take to show results?
At least 3 months, and 6 months is a more sensible point for evaluation because follicles work in long cycles. That is why daily consistency matters more than having the “perfect” product and using it whenever you remember. A progress photo every three months in the same lighting is one of the best ways to track change.
Does biotin make hair grow?
Biotin contributes to the maintenance of normal hair, and supplementation is most relevant when there is a deficiency or nutritional strain from restrictive dieting or stress. That is why serious hair supplements tend to combine nutritional support with functional actives such as Saw Palmetto, which target other pathways involved in male hair loss.
Can lost hair grow back?
It depends on the follicle. If it is weakened or miniaturised, it may respond to consistent treatment. If an area has been inactive for years and the scalp is smooth and shiny, a transplant may be the realistic option. That is why acting early can make such a difference.
When should I see a dermatologist?
If the shedding is sudden, patchy, accompanied by scalp symptoms or you are losing hair elsewhere on the body, get it checked. It is also sensible to go early if you notice a progressive pattern compatible with androgenetic alopecia and want to discuss the options with the strongest evidence.
Sources and evidence
To separate what we know reasonably well from what is still being investigated, we have used scientific reviews, medical literature and primary ingredient documentation:
- Kaiser M. et al. Treatment of Androgenetic Alopecia: Current Guidance and Unmet Needs (2023).
- Gupta A.K. et al. Relative efficacy of conventional monotherapies and nonconventional products for male androgenetic alopecia (2025).
- Telogen Effluvium — a review of the science and current obstacles (2021).
- Evron E. et al. Natural Hair Supplement: Friend or Foe? Saw Palmetto, a systematic review (2020).
- Lucas Meyer Cosmetics. Capixyl™ — ingredient documentation.
- EU Regulation 432/2012 — authorised health claims for nutrients, including biotin and zinc.
So, what now?
If you have made it this far, you already care about your hair more than the average bloke. Start today with whichever layer your routine is missing and take that first progress photo. Your ten-years-from-now self may well thank you. With interest.
Start my hair-loss routineNote: this content is for general information and education only and does not replace diagnosis or advice from a healthcare professional. Food supplements should not be used as a substitute for a varied, balanced diet and a healthy lifestyle. If your hair loss is sudden, patchy, progressive or accompanied by other symptoms, speak to a healthcare professional.