Hair and Skin

What is the difference between hair shedding and hair thinning?

Hair shedding is losing more hairs than usual while the follicles themselves stay healthy; hair thinning is the individual hairs becoming progressively finer as susceptible follicles miniaturize. Shedding starts fairly suddenly, is diffuse across the whole scalp, and usually reverses once its trigger is corrected. Thinning develops over years, shows as a widening part line in women or recession at the temples in men, and is progressive without treatment. The two frequently coexist, which is why a shedding episode often reveals thinning nobody had noticed.

Shedding or thinning

Why did my hair start falling out months after I was ill?

A delay of roughly two to three months between a trigger and the hair loss is the defining feature of telogen effluvium, the shedding pattern. A significant stressor — illness, surgery, iron depletion, a thyroid change, rapid weight loss, childbirth — pushes an unusually large share of follicles into the resting phase at once, and they release their hairs together at the end of it. The event that caused it has usually been forgotten by the time the hair comes out, which is why it is worth thinking back a season rather than a week.

Shedding or thinning

Will hair grow back after shedding?

Hair lost to shedding usually grows back, because telogen effluvium does not damage the follicle — once the trigger is corrected, the follicles re-enter the growing phase. Full recovery takes roughly six to twelve months, which is simply how long hair takes to grow, so nothing useful can be judged in weeks. Pattern thinning behaves differently: it does not reverse on its own and tends to progress without treatment.

Shedding or thinning

Can a GLP-1 medication cause hair loss?

Rapid weight loss is a well-recognized trigger for hair shedding, and weight loss on a GLP-1 medication is no exception — the shedding typically appears two to three months after the weight starts coming off. It is a shedding pattern rather than permanent loss, and it generally settles as weight stabilizes and intake becomes adequate again. Protein intake and ferritin are both worth checking, because under-eating during rapid loss makes it more likely. Other effects of GLP-1 treatment are covered in the weight loss questions.

Shedding or thinning

Why is my hair thinning after 50?

Hair after 50 usually changes for several reasons at once: susceptible follicles miniaturize as estrogen falls and leaves normal androgen levels less opposed, the total number of follicles declines with age, the growing phase shortens, and a correctable deficiency is frequently sitting on top of all of it. The age-related part is not reversible; the deficiency part often is, which is why a panel before a product is the productive order. Scalp redness, scaling, pain, discrete round bald patches, or smooth shiny skin where follicle openings have disappeared are different problems that need prompt assessment rather than pattern-loss treatment.

Why hair thins after 50

Which hormones cause hair loss in women?

No single hormone causes hair loss in women, and the commonest mechanism is a shift in balance rather than an abnormal level. Female androgen levels decline gradually with age rather than rising at menopause; estrogen falls faster and further, so the androgens that remain act with less opposition at genetically susceptible follicles. Thyroid disease — both underactive and overactive — and raised prolactin are separate and genuinely testable causes, which is why thyroid function belongs on every hair panel. Testosterone is worth measuring alongside SHBG, because SHBG determines how much of it is free and active.

The hormones behind hair loss in women

My hormone panel was normal but my hair is thinning. What does that mean?

A normal hormone panel is the usual finding in female pattern hair loss, and it does not mean hormones are uninvolved. What changed is follicle sensitivity and the balance between estrogen and androgens, and no blood test measures either. It does mean there is no hormone level to treat, and that the productive next steps are ferritin, thyroid function, and an honest look at whether what is happening is shedding rather than thinning.

The hormones behind hair loss in women

Does low ferritin cause hair loss?

Iron deficiency is genuinely associated with hair shedding, and correcting a real deficiency is often followed by improvement — hair follicles are among the most metabolically demanding tissues in the body and are deprioritized early when iron stores fall. What is not established is the specific ferritin level below which hair is affected; the figures that circulate are quoted with far more confidence than the evidence supports. Ferritin is worth checking in anyone who is shedding, read alongside transferrin saturation and inflammatory markers rather than on its own, because ferritin also rises with inflammation and can look acceptable while stores are genuinely depleted.

Ferritin and hair loss

Can my iron be low if my blood count is normal?

Yes, and it is the most commonly missed finding in hair loss. Ferritin reflects stored iron and falls well before hemoglobin does, because the body keeps prioritizing red cell production while the stores empty — so a normal blood count is entirely compatible with real depletion. Ferritin is not on most standard panels and has to be asked for, which is why people are told their iron is fine when it has not been measured.

Ferritin and hair loss

What ferritin level do I need for my hair?

ACT 2 Health does not publish a ferritin target for hair, because the figures in circulation come largely from small studies and expert opinion rather than outcome data — and printing one is how a normal result gets turned into a reason to sell something. A frank iron deficiency is worth correcting on its own merits, whatever it is doing to your hair. A ferritin that reads acceptable in someone with active shedding means looking elsewhere. And why iron is low matters as much as how low it is: in a man or a postmenopausal woman, unexplained iron deficiency warrants investigation of the gastrointestinal tract.

Ferritin and hair loss

Do hair growth supplements work?

Hair supplements help where they correct a genuine deficiency and have weak evidence otherwise. High-dose biotin, which is in most of them, does nothing for hair in a person who is not deficient and interferes with several thyroid and hormone blood tests — so it can produce a misleading result on the very panel being used to find the cause. Excess selenium and excess vitamin A both cause hair loss, so more is not safer here.

Why hair thins after 50

Is the 4-in-1 hair loss treatment FDA-approved?

No. The ACT 2 Health 4-in-1 hair loss preparation is a compounded medication, and no claim made for a branded hair-loss product transfers to it. Compounded medication. Prepared by a licensed compounding pharmacy under a prescription written for you. Compounded medications are not FDA-approved, are not reviewed by the FDA for safety or effectiveness, and are not equivalent to or interchangeable with any branded product. Prescribed only when a licensed provider determines it is medically appropriate.

4-in-1 hair loss treatment

Is topical finasteride as effective as oral finasteride?

In its phase 3 trial, topical finasteride was comparably effective to the oral form on scalp hair count over six months, while lowering blood DHT by roughly a third rather than by half or more. Less systemic exposure is not zero systemic exposure: topical finasteride is absorbed, and the FDA issued an alert in 2025 on compounded topical finasteride products following reports of persistent sexual and mood effects. Which route suits you is a clinical decision that takes your history into account rather than a preference.

Topical versus oral finasteride

How common are sexual side effects with finasteride?

A minority of men taking finasteride report reduced libido or erectile difficulty, and in the pivotal trials the excess over placebo was under two percentage points. Most men who develop them find they resolve, either on continued use or after stopping. They are worth reporting to your prescriber promptly rather than waiting for a scheduled review, because the response depends on why you are taking it and what else you are taking.

Finasteride and sexual side effects

Are finasteride side effects permanent?

Usually not — most sexual side effects from finasteride resolve after stopping. Symptoms persisting after discontinuation have been reported, appear on the label, and are described as post-finasteride syndrome; how often they occur and whether the drug causes them directly are genuinely unresolved, and anyone who tells you the question is settled in either direction is ahead of the evidence. ACT 2 Health discloses the debate before prescribing and monitors for it rather than treating it as a non-issue. A history of depression or another mood disorder is worth raising before starting, because mood changes have also been reported.

Finasteride and sexual side effects

Can women take finasteride for hair loss?

No — finasteride and other 5-alpha-reductase inhibitors are teratogenic, meaning they can cause serious birth defects affecting development in a male fetus, and women who are pregnant or may become pregnant must neither take them nor handle them. The same caution applies to topical preparations, which can transfer through skin contact; the FDA's 2025 alert on compounded topical finasteride flagged exposure of a pregnant partner specifically. Women with hair thinning in midlife are better served by a hormonal and nutritional assessment, since the common causes are different.

Topical versus oral finasteride

Does finasteride affect a PSA test?

Yes — finasteride and other 5-alpha-reductase inhibitors roughly halve PSA, so a reading taken without accounting for that understates the true value by about half. This matters most for men on testosterone replacement therapy, where PSA is monitored as part of prostate assessment and an unflagged halving could mask a finding the monitoring exists to catch. Tell whoever monitors your prostate that you are taking it, and assume a hair-loss preparation contains a 5-alpha-reductase inhibitor until your clinician tells you otherwise. It is also an argument for getting hair treatment and testosterone therapy from a clinician who can see both prescriptions.

4-in-1 hair loss treatment

Is oral minoxidil safe for the heart?

For a healthy adult with a normal heart, serious cardiovascular events on oral minoxidil used for hair have been rare in the large safety series — but minoxidil is a vasodilator that carries a boxed warning at blood-pressure-treating strengths, and careful selection of who takes it is what keeps it safe. It is not appropriate for anyone with heart failure, a recent cardiac event, uncontrolled or low blood pressure, a history of pericardial disease, or significant kidney disease, and anyone else with a cardiovascular history needs an ECG and a clinician's decision first. Topical minoxidil is absorbed at a fraction of the oral amount and rarely affects the heart. Report palpitations at rest, ankle or facial swelling, breathlessness lying flat, chest pain, or dizziness on standing to your prescriber before taking any more.

Minoxidil and the heart

Can I use estradiol cream on my face for wrinkles?

ACT 2 Health does not prescribe estradiol or estriol cream for facial skin. Estrogen genuinely matters to skin — it drives collagen production and hydration, and the fastest collagen loss of adult life happens in the first years after menopause — but applying a hormone to the face delivers it systemically, in an uncontrolled amount, without the progesterone protection that systemic therapy requires for a woman with a uterus. The trials behind facial estrogen were small, short and mostly decades old, and none was designed to answer that safety question. A woman already on systemic estradiol who wants to know whether her prescribed product may go on her face should ask her clinician rather than assume.

Estrogen face cream

Do peptides improve skin?

No peptide has been shown to reliably improve skin, and ACT 2 Health does not prescribe one for appearance. Marketing in this category routinely blurs topical cosmetic use with clinician-guided prescription therapy, and evidence from a skincare study does not transfer to a therapeutic claim. What does have evidence behind it for midlife skin is unglamorous: daily broad-spectrum sunscreen, a topical retinoid, barrier-restoring moisturizers, and — for women who qualify on other grounds — systemic hormone therapy, where better skin is a side benefit rather than the reason. Questions about individual compounds are answered in peptides by name.

Peptides for skin and hair

Results vary. Clinical trial results apply only to the FDA-approved branded medication specifically identified and do not apply to compounded medications. All medications must be prescribed by a licensed provider based on medical necessity.