Shedding After Starting Hair Loss Treatment: Is It Normal?

In short: yes, a temporary increase in shedding during the first weeks of topical treatment is a documented phenomenon. The only study to test it directly followed 49 patients on 2% or 5% topical minoxidil for 24 weeks and found the increase concentrated in the first 12 weeks, lasting longer at 2% than at 5%. In that study, the peak amount of shedding was significantly associated with later improvement — so there is a basis for "shedding means it is working", but the basis is one small retrospective study, and nothing more than that. More importantly: not all early shedding is this phenomenon. If shedding begins before treatment started, continues past three months, comes with other symptoms, or is diffuse across the whole scalp, that is a separate clinical question that needs investigating rather than waiting out.

Almost every man who starts treatment for hair loss hits the same moment. Two or three weeks in, there is more hair in the sink, not less. The instinctive response is to stop — something has clearly got worse. The problem is that stopping at this point guarantees the treatment will not work, regardless of whether it would have.

Search for an explanation and you will find pages telling you, with complete confidence, that this is a good sign. Some of them are written by people selling the product. None of them mentions how large the study behind that claim actually is. Here is the same question as a clinician looks at it.

Why does shedding increase when treatment starts?

This needs one sentence about the hair cycle. Every follicle alternates between an active growth phase (anagen) and a resting phase (telogen), at the end of which the hair is released and makes way for a new one. At any given moment a proportion of the follicles on your scalp are resting.

Topical minoxidil acts, among other things, on that transition: it shortens the resting phase and pushes dormant follicles back into growth earlier than they would have gone. The comprehensive review of minoxidil describes it as working through several pathways at once — vasodilation, anti-inflammatory activity, induction of the Wnt/β-catenin pathway — and notes that it may also alter the length of both the anagen and telogen phases (PubMed 34159872).

That is the explanation. A resting hair is still sitting in its follicle. If the follicle is pushed back into growth early, the old hair is pushed out — and a lot of them go at roughly the same time. The result is a concentrated wave of hairs that were going to be shed over the following months anyway, arriving at once instead of spread out. It is not the loss of new hair; it is the synchronisation of shedding that was already coming.

How long does it last, and what was actually measured?

This is the question no ranking page answers with a number you can check, and it is answerable.

In 2025, the first study to examine the phenomenon directly was published. Researchers followed 49 patients using 2% or 5% topical minoxidil for androgenetic alopecia over 24 weeks, recording the amount of shedding every four weeks before and during treatment. The findings (PubMed 40122142):

• A temporary increase in shedding was detected, and it was concentrated in the first 12 weeks.
• The increase lasted longer in patients using 2% than in those using 5%.
• The maximum relative amount of shedding was significantly associated with improvement in BASP classification — in both concentration groups. In other words, the men who shed more during this phase tended to improve more later.
• On trichoscopy, that association held only in the 5% group, not the 2% group.

What this means in practice. There is a research basis for saying the shedding phase is linked to a better response. But that basis is a single retrospective study of 49 people. For comparison, the evidence that topical minoxidil works at all rests on a randomised, double-blind, placebo-controlled trial in 393 men over 48 weeks (PubMed 12196747). So: that the treatment works is well established. That early shedding predicts it will work is plausible, interesting, and far less established. Anyone presenting it as settled fact is selling you a certainty they do not have.

When is it not the expected phase?

This is the important part, and it is the part almost nobody writes — because it ends in a referral for tests rather than in continued use.

Increased shedding can have causes with nothing to do with treatment. Telogen effluvium — where an unusually large share of follicles enters the resting phase at once — is triggered by illness or fever, surgery, sharp weight loss, significant psychological stress, certain medications, and by nutritional deficiency and thyroid dysfunction. In a series of 3,028 patients with telogen effluvium, the most frequently performed test was serum ferritin (82.3%), followed by full blood count (81%); 6.2% of patients had iron deficiency anaemia and 4.6% had thyroid dysfunction (PubMed 34449961). That cohort was predominantly female, so the prevalence figures do not transfer directly to men — but the principle does: before assuming shedding is "the expected phase", it is worth confirming there is no other cause.

The table below sets out the practical difference.

	The expected shedding phase	Needs clinical assessment
When it starts	Usually within the first weeks after starting topical treatment	Begins independently of any treatment, or first appears after month 4
Duration	Bounded — in the study above, concentrated in the first 12 weeks	Continues beyond three months, or worsens over time
What the hairs look like	Whole hairs with a small white bulb at the root, mainly from treated areas	Diffuse across the entire scalp, or hairs breaking mid-shaft
Accompanying symptoms	None	Fatigue, weight change, cold intolerance, scalp itch, redness, pain or unusual scaling
Context	You started treatment and the shedding followed	Preceded by illness, surgery, crash dieting, major stress or a new medication
What to do	Continue as directed and tell your clinician	Seek assessment — usually basic blood tests before continuing

Should you stop treatment because of shedding?

That is a clinical decision rather than one to make alone at the bathroom sink, but it helps to understand the logic on both sides.

On one side: if this is the expected phenomenon, stopping at week four removes any chance of seeing the outcome the research describes, which is measured in months rather than weeks. The 48-week trial cited above assessed men over nearly a full year. The shedding study followed patients for 24 weeks. Those are the relevant timescales.

On the other: if the shedding is not the expected phenomenon — if it started before treatment, if it is diffuse rather than localised, if it comes with other symptoms — then waiting longer is not patience, it is a delayed diagnosis. That is also a clinical consideration.

So the practical answer is neither "stop" nor "push through regardless", but: tell the clinician who prescribed the treatment, and give them three specifics — when the shedding started relative to starting treatment, how long it has been going on, and what it looks like. Those three details are usually enough to tell the two situations apart.

Why do some men never see it at all?

That is also normal, and on its own it means nothing. In the study described, not every participant showed the same intensity, and the concentration used affected how long the phase lasted.

There is also a well-recognised biological factor. Minoxidil is a prodrug — it is not active as applied. An enzyme in the hair follicle, sulfotransferase, converts it to minoxidil sulfate, the active form. Sulfotransferase activity varies between individuals, and those with higher activity may respond better than those with lower activity (PubMed 34159872). This is one of the explanations for the wide variation in response between patients — and it is part of why matching a treatment to a person is a medical decision rather than a selection from a list.

Frequently asked questions

Is increased shedding at the start a sign the treatment is working?

There is a research basis for this, but a more modest one than it is usually given. In a 2025 retrospective study following 49 patients over 24 weeks, the maximum amount of shedding was significantly associated with later improvement in BASP classification (PubMed 40122142). That is the only study to have tested the question directly, and it is small and retrospective. So: a plausible association, not a certainty.

How long does the increased shedding last?

In that study, the increase was concentrated in the first 12 weeks, and lasted longer at 2% concentration than at 5%. Shedding that continues beyond that, or that worsens, is worth raising with your clinician rather than waiting out.

I am shedding more but I have not started topical treatment — what is that?

That is a different question entirely. Increased shedding unrelated to starting treatment can be telogen effluvium, triggered by illness, surgery, sharp weight loss, significant stress, certain medications, iron deficiency or thyroid dysfunction. In a series of 3,028 telogen effluvium patients, 6.2% had iron deficiency anaemia and 4.6% had thyroid dysfunction (PubMed 34449961). This warrants assessment rather than waiting.

Do the hairs shed during this phase grow back?

The accepted explanation is that the hairs pushed out during this phase were resting hairs anyway, and the follicle itself stays in place and returns to growth. That differs from an area where follicles have already fully miniaturised, where there is nothing to return. A clinician can assess the state of the follicles in the treated area.

If I get no shedding at all, does that mean it is not working?

No. Not everyone develops the phenomenon, and its absence does not predict failure. The study asked whether the amount of shedding correlates with improvement — not whether its absence rules improvement out. Those are two different questions, and the second one was not tested.

What should I tell my clinician when I report this?

Three things: exactly when the shedding started relative to starting treatment, how long it has been going on, and whether there are any other symptoms — fatigue, weight change, scalp itch or redness. Those three are usually enough to separate the expected phase from something that needs investigating.

The bottom line

A temporary increase in shedding during the first weeks of topical treatment is a documented phenomenon, and it is well explained by the way the medicine shortens the follicle's resting phase. There is also preliminary evidence — one study, 49 participants — that the intensity of that shedding is linked to a better response. What there is not, is certainty. What matters more is the distinction: the expected phase begins after treatment starts, is bounded in time, and comes with no other symptoms. Shedding that fails any of those three tests is not "a stage to get through" — it is an open clinical question, and often basic blood tests are enough to answer it.

Medical disclaimer: the information on this page is general medical information and does not constitute personal medical advice, diagnosis or a treatment recommendation. Treatment suitability is determined by a clinician based on your individual circumstances. Do not start, change or stop treatment on the basis of this page. A full list of possible side effects for any prescribed medicine appears in the Ministry of Health–approved consumer leaflet, available from the Ministry's drug registry.

Sources: Bi L, Kan H, Wang J, et al. Whether the transient hair shedding phase exist after minoxidil treatment and does it predict treatment efficacy? A retrospective study in androgenetic alopecia patients. J Dermatolog Treat. 2025;36(1):2480739 — PubMed 40122142 · Minoxidil: a comprehensive review. J Dermatolog Treat. 2022;33(4):1896-1906 — PubMed 34159872 · Olsen EA, Dunlap FE, Funicella T, et al. A randomized clinical trial of 5% topical minoxidil versus 2% topical minoxidil and placebo in the treatment of androgenetic alopecia in men. J Am Acad Dermatol. 2002;47(3):377-385 — PubMed 12196747 · Telogen effluvium in daily practice: patient characteristics, laboratory parameters, and treatment modalities of 3028 patients with telogen effluvium. J Cosmet Dermatol. 2022;21(6):2610-2617 — PubMed 34449961 · Israel Ministry of Health drug registry and consumer leaflets: israeldrugs.health.gov.il