“More Hair Started Falling Out After I Began Treatment” — Is It a Sign of Failure? The Medical Mechanism of Initial Hair Shedding and Stem Cell Conditioned Media as an Option2026.06.27

“I just started treatment and now my hair is shedding even more than before” — this is by far the most common worried voice we hear from patients who have just begun AGA treatment or stem cell conditioned media therapy. Despite starting with high hopes, seeing more hair in the shower drain or on the pillow makes anyone wonder, “Did the treatment fail? Was it the wrong choice for me?”

This phenomenon is medically called initial hair shedding (also known as “shedding”), and it is now understood as a kind of “positive reaction” that occurs while the hair cycle is being re-synchronized by the treatment. In this article, Dr. Moriwaki of AVAN TOKYO medically organizes why shedding happens, how long it tends to last, and how patients should approach it.

What Is Initial Hair Shedding? The True Nature of Increased Loss Right After Treatment Starts

The phenomenon in which hair fall transiently increases shortly after starting a treatment that intervenes in the hair cycle — such as minoxidil, finasteride or stem cell conditioned media — typically within the first two to eight weeks, is medically called shedding.

Normally each hair cycles through anagen (growth), catagen (regression) and telogen (rest) phases on its own independent timing. On a scalp where hair loss is progressing, however, many follicles that should be in anagen have drifted into catagen or telogen, and “miniaturization” — a process in which hairs become thinner and shorter — is already underway.

When treatment begins, follicles that had been stuck in telogen all receive the signal to “enter the next anagen phase” almost simultaneously. New thicker hairs push up from below and physically displace the old, thin hairs that had been sitting in telogen — this is the essential mechanism of initial hair shedding.

Not “Hair Is Lost” but “A Sign That New Hair Is About to Grow”

In other words, this is not a process of losing hair but a process of preparing for the next generation of hair. What is falling out are “telogen hairs that had already finished their role,” and underneath them new anagen hairs are pushing upward.

This phenomenon has long been reported with topical and oral minoxidil, and in recent years similar changes have also been observed with stem cell conditioned media therapy. Growth factors, cytokines and exosomes activate follicular stem cells and promote the transition from telogen back into anagen (anagen induction).

When Does Initial Hair Shedding Begin, and When Does It Settle?

The onset and duration of shedding vary between individuals, but the rough timeline is becoming clearer.

A Guide to Timing and Duration

With minoxidil treatment, many patients notice an increase in shedding two to four weeks after starting, with a peak at four to eight weeks, and the situation settles down naturally by around twelve weeks. With stem cell conditioned media therapy, similar increases in hair fall are sometimes reported three to six weeks after the first or second session.

That said, shedding does not happen in every patient. Clinically, it tends to be more pronounced in those who already have rapid progression, a high proportion of telogen hairs, or a young, active hair cycle. On the other hand, in patients whose progression is slow and whose miniaturization is still mild, many barely notice it.

How to Distinguish “Failure” From “Genuinely Insufficient Effect”

The key points for distinguishing transient initial hair shedding from a treatment that truly is not working are “duration” and “hair quality.”

If shedding does not subside even after three months, or if there is no sign that new hairs are growing back thicker or longer than before, it is time to reconsider the treatment protocol. Conversely, if the shedding is transient and patients begin to feel that “hair diameter has thickened” or that “the parting is less visible” after three months, this can be judged as a sign that the treatment is working — they have simply moved through the shedding phase.

For overall AGA treatment guidelines, the clinical guidance published by the Japanese Dermatological Association is also a useful reference.

From the Clinic — Designing Treatment with Initial Hair Shedding in Mind

At AVAN TOKYO, we always explain to patients before starting stem cell conditioned media therapy that initial hair shedding may occur. Simply knowing about it in advance dramatically reduces the psychological shock of facing increased hair fall in the following weeks.

Quitting During the Shedding Phase Is the Greatest Loss

Stopping treatment at this stage is the most regrettable decision a patient can make. If the cycle has just begun moving and treatment is halted, the follicles that were about to enter anagen will return to telogen, and the only impression left will be the mistaken one that “treatment caused my hair to fall out.”

What matters is evaluating on a three- to six-month timescale. One or two months is far too short to judge results. Dr. Moriwaki tells patients from the first consultation that “objective evaluation requires at least three months” and recommends tracking progress with standardized fixed-point photography and hair diameter measurement.

Can Initial Hair Shedding Be Made Milder by Design?

It is in principle difficult to bring shedding down to zero, but the surprise can be minimized by design: improving the scalp environment before starting treatment, adjusting the induction-phase interval, and introducing combinations with topical minoxidil gradually so the protocol matches each patient’s hair cycle and sensitivity.

Stem cell conditioned media supports follicles by delivering growth factors and cytokines directly to the microenvironment, helping them escape from telogen. Combined with Morpheus8 drug delivery, the active ingredients can also be guided into deeper layers. The real key to treatment success is reframing shedding not as “a sign to quit” but as “a sign that new hair is about to come in.”

We cover related themes in more depth in other articles. Please also see the related columns on hair regenerative medicine here. Correctly understanding phenomena like initial hair shedding during the course of treatment is what leads to long-term success.

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【監修】森脇 進 / Shin Moriwaki (Supervising Physician)

Member, Japan Society of Aesthetic Surgery (JSAS) / Member, American Academy of Aesthetic Medicine

U.S. Medical Licensure Qualification (ECFMG Certificate)

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📍AVAN TOKYO Ginza Hair Regenerative Medicine

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