Three Pitfalls in the Hair Treatment Evaluation Design of Stem Cell Conditioned Media — Reviewing Timing, Records, and Photo Conditions Before Concluding It Is Not Working, Organized by Dr. Moriwaki2026.08.15
“It has been several months since I started treatment, but when I look in the mirror I do not really feel it has changed.” We often hear this from patients continuing hair treatment with stem cell conditioned media. Before concluding that it is “not working,” however, there is one thing we ask you to pause and check. It is not the treatment content itself, but rather the hair treatment evaluation design — the framework of what to observe, when, and under what conditions. When the evaluation design is loose, changes that are actually occurring may go unnoticed, and conversely, changes that are not occurring may be perceived as real. In this article, Dr. Moriwaki organizes, from a clinical viewpoint, three typical pitfalls in the hair treatment evaluation design that must not be missed if you want to properly judge the effect of stem cell conditioned media, along with a minimum re-evaluation set you can start setting up today.
Key Points of This Article
・The hair treatment evaluation design is “the other half that is as important as the treatment itself,” and if this is loose the accuracy of the effect judgment drops significantly
・The reason effect evaluation tends to be too early is a physical constraint of the hair cycle: it takes at least 3–4 months for a newly anagen hair to appear on the scalp surface at a “visible thickness and length”
・Subjective mirror comparison, smartphone auto-correction, and lighting variability all falsely portray change — in both directions of increase and decrease
・With fixed-point photography and microscope records under standardized conditions every 3–4 months, even the physician can make an objective judgment
・Discontinuing treatment on one’s own judgment as “not working” while records are scarce is one of the biggest reasons that treatments which would otherwise have succeeded are lost to early dropout
What Happens When the Hair Treatment Evaluation Design Is Loose — The Hair Cycle and the Timeline of Stem Cell Conditioned Media
Before discussing hair treatment evaluation design, let us organize why “premature evaluation” happens at all, using the time axis of the hair cycle. Human hair cycles through anagen, catagen, and telogen phases, and what stem cell conditioned media mainly acts on is the follicular microenvironment, including hair follicle stem cells and the dermal papilla. Even if signaling begins to move there, it often takes at least 3–4 months — and 6 months or more depending on site and progression — for hairs newly entering anagen in that follicle to actually emerge on the scalp at a “visible thickness and length.” In other words, concluding that treatment is “not working” at 1–2 months from the start can mean judging that hair is not growing before it has even had a chance to appear.
Furthermore, there are cases in which a temporary increase in shedding at 2–8 weeks after starting treatment (initial shedding) is misinterpreted as “worsening,” leading to dropout. This is a known phenomenon in which telogen hairs are pushed out by new anagen hairs, and as referenced in the AGA guidelines from bodies such as the Japanese Dermatological Association, it is not necessarily a sign of failure. Correctly understanding the time axis medically is the first step of the hair treatment evaluation design.
Three Typical Pitfalls in the Hair Treatment Evaluation Design With Stem Cell Conditioned Media
1. Evaluation Timing Is Too Early
The most common case is a judgment made at 1–2 months after starting. Ignoring the physical constraints of the hair cycle and repeating subjective judgments in front of the mirror easily misidentifies the period “before change appears” as the period of “no effect.” At our clinic, the first effect check is at 3 months from the start of treatment, the main assessment at 6 months, and thereafter every 3–4 months in line with the hair cycle. Of course, individual variation exists, and the time axis shifts depending on progression and age.
2. Records Are Missing
The feelings of “I somehow feel it increased” or “I somehow feel it decreased” are, by the nature of memory, heavily influenced by the scalp condition, mood, and lighting environment of the last few days. If there is no baseline record of photos, hair diameter, and subjective symptoms at the start point, there is no starting line to compare against. Only when both microscope images and self-fixed-point photography are kept at each visit does evaluation based on images and numbers, rather than subjectivity, become possible.
3. Shooting and Observation Conditions Are Inconsistent
If progress photos taken at home are taken with different lighting, different angles, and different hairstyles every time, comparison “under the same conditions” cannot be made even if each single photo is clean. Indoor fluorescent light, natural light, and backlight make the same scalp look completely different. Fixed-point photography only becomes meaningful when all five conditions are aligned: same location, same time of day, same light source, same hairstyle (dry, part fixed), and same camera position. For details on shooting conditions, please also see our related column list on hair regenerative medicine.
Three Steps to Set Up Your Hair Treatment Evaluation Design Today
Setting up the hair treatment evaluation design does not require special equipment. The following three steps can build a fully functional framework.
First, a starting-line record at the initial visit. Fix as baseline the hair diameter measurement by microscope, multiple angle photos of the crown, hairline, and vertex, and scoring of subjective symptoms (itch, shedding amount, ease of styling). If this is left vague as treatment proceeds, it becomes difficult even to discuss “worked” or “did not work” later.
Second, once-a-month self-fixed-point photography. On a fixed day of the week and time of day, in front of the same wall at home, with hair dried and the part fixed, take one photo each of the crown and hairline. Even just fixing the smartphone on a stand greatly improves precision.
Third, a formal evaluation by a physician every 3–4 months. This includes direct comparison with the baseline, microscope-based hair diameter and hair counts per follicular unit, and if needed, blood tests and lifestyle reconfirmation. Only here can judgments of “continue,” “change the interval,” “add another treatment,” or “stop / graduate” be made medically.
What matters is: when you feel that change is scarce, before reflexively choosing “stop,” first check whether “the evaluation design itself is functioning.” If treatment is discontinued while there are holes in the evaluation design, the same judgment tends to repeat itself even at the next clinic. Individual variation and limits in efficacy are premises, but if the judgment is not based on proper evaluation, the value of that judgment itself drops.
Frequently Asked Questions
Q. It has been two months since I started treatment, and I do not feel it has changed at all. Should I stop?
Not seeing change at two months is not a sign of failure. In many cases, it simply has not reached the “visible stage” on the hair cycle. We strongly recommend postponing judgment at least until the physician evaluation at 3–4 months.
Q. Would daily fixed-point photography improve precision?
Even taking photos every day, appearance changes with daily humidity, styling products, and drying after bathing, which actually causes judgment to fluctuate. Photos taken once a month under the same conditions make long-term trends easier to read.
Q. In terms of “feeling that it works,” what appears first?
In many patients, changes in hair quality (firmness, thickness) and ease of styling appear before changes in hair volume (count). Knowing this order helps you avoid overlooking small early changes.
Q. How much should I trust the numbers from microscopes or hair density measurement apps?
Numbers are more objective than subjectivity, but they depend heavily on shooting conditions and software algorithms. Please understand them as relative values that become meaningful only when measured continuously with the same device, same conditions, same site.
Q. Continuing to record is a burden. Is there a minimum you would recommend?
Even just two monthly photos of the crown and hairline, along with a monthly subjective symptom score (a simple 10-point scale for shedding amount and appearance satisfaction), is sufficient as the foundation for the evaluation design. Continuing within a manageable range is what matters most.
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Supervised by: Dr. Shin Moriwaki (Supervising Physician)
Member, Japan Society of Aesthetic Surgery (JSAS) / Member, American Academy of Aesthetic Medicine
ECFMG Certificate
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