Is Your Stem Cell Conditioned Media Hair Treatment Registered Under Japan’s Regenerative Medicine Safety Act? Dr. Moriwaki Clarifies Class I/II/III Risk Classifications and How Patients Can Verify Public Filings2026.07.26

“Is this stem cell conditioned media hair treatment I’m about to receive properly registered under the law?” Very few patients think to ask themselves this question amid the flood of advertising and testimonials in regenerative medicine. In Japan, treatments using processed human cell products offered as self-pay care must, in principle, be provided within the framework of the Regenerative Medicine Safety Act, and stem cell conditioned media hair treatments are deeply intertwined with this regulatory structure. In this article, supervising physician Dr. Shin Moriwaki outlines the Act’s overall design, where conditioned media treatments sit within the Class I / II / III risk classification, and how patients can verify the relevant public information themselves.

Key Points of This Article

・The Regenerative Medicine Safety Act, enforced in 2014, is Japan’s law governing self-pay treatments that use processed human cell products.

・A three-tier risk classification (Class I high risk / Class II moderate risk / Class III relatively low risk) is defined; however, because stem cell conditioned media itself contains no cells, the prevailing interpretation is that its administration does not directly fall within the Act’s scope.

・That said, the facility that manufactures the conditioned media handles cells and may need to be registered as a designated cell processing facility with a regional bureau of Health, Labour and Welfare — this is where transparency becomes visible to patients.

・Rather than being swayed by advertising phrases like “MHLW-approved,” patients should learn to verify three things themselves: registration information, the manufacturing facility, and lot-level quality testing.

What Does the Regenerative Medicine Safety Act Actually Protect?

This law was established so the government could monitor and oversee — from both safety and ethical perspectives — treatments that process human cells such as iPS cells, ES cells, or somatic stem cells and administer them to patients. Enforced in 2014, it introduced rules to what had been a grey zone of self-pay cell therapy. For each treatment protocol, medical institutions must prepare a Regenerative Medicine Provision Plan, have it reviewed by a certified Regenerative Medicine Committee, and file it with the Minister of Health, Labour and Welfare (in practice, the relevant regional bureau).

The law is designed to protect patient safety and the quality of care by placing three layers of safeguards — facility, records, and review process — against risks unique to cell products, such as microbial contamination, cell degeneration, or unexpected immune reactions. It is important for patients to understand that this is not a law that guarantees the therapeutic effect itself.

Class I, II, and III Risk Classification: Where Do Conditioned Media and Exosomes Sit?

Under this law, treatments are sorted into three risk tiers. Class I covers treatments with high risk and limited precedent, such as those using iPS, ES, or allogeneic cells. Class II covers moderate-risk treatments, such as the administration of autologous or allogeneic somatic stem cells. Class III covers relatively low-risk treatments, such as minor processing of somatic cells returned to the same patient. The depth of review, reporting duties, and committee composition each scale with the tier.

The Difference Between Transplanting Cells and Using Their Secretions (Conditioned Media)

What matters here is that stem cell conditioned media is the supernatant of the culture medium — it contains no cells. Since the law governs the act of administering “processed human cell products” to a person, the administration of a cell-free supernatant is, under the current interpretation, generally considered outside the direct scope of the Act, and it does not directly correspond to the Class I–III risk classification either. However, this remains a matter of ongoing regulatory and practical debate, and MHLW notices and expert committee views may be updated over time, so it is unwise to state this as an absolute conclusion. Similar discussions are underway regarding exosome preparations, given their nature as extracellular vesicles.

Public Information Patients Can Verify — Transparency in Manufacturing and Quality Control

Even if the administration of the conditioned media itself is not directly regulated, cells are cultured during its manufacturing. It is desirable for the manufacturing facility to be registered with the regional bureau as a designated cell processing facility, and reputable manufacturers publicly disclose this. Before treatment, patients can verify the following:

・The name and location of the facility that manufactures the conditioned media

・The registration number of the manufacturing facility, or a clear statement that it is registered

・Whether per-lot quality testing (sterility, mycoplasma, endotoxin, etc.) is performed

・Whether the Certificate of Analysis (CoA) for the lot used will be provided upon request

Whether these details are clearly stated on the clinic’s website, in the contract, and in the pre-treatment explanation is one indicator of the clinic’s overall posture. A companion index of columns on hair regenerative medicine is published here, addressing related topics on quality, manufacturing, and evidence.

“MHLW-Approved” and “Registered” Are Not the Same — A Common Advertising Pitfall

Advertising phrases such as “approved by the Ministry of Health, Labour and Welfare” or “government-approved treatment” often actually mean “registered,” but approval and registration are legally distinct concepts. Approval (marketing authorization) for pharmaceuticals or regenerative medicine products clears a very high bar; registration simply means the required documents have been submitted. The framework of the Regenerative Medicine Safety Act is likewise a registration system, so the mere fact of registration does not mean the government has guaranteed the treatment’s safety or efficacy. Japan’s medical advertising guidelines prohibit misleading expressions, and patients should understand the distinction. For general guidelines on AGA and hair loss care, the Japanese Dermatological Association is a useful reference.

Five Questions Patients Should Ask About Stem Cell Conditioned Media Hair Treatment

Building on the above, five questions are worth asking directly at the clinic. First, the cell source of the conditioned media (umbilical cord, adipose, dental pulp, etc.) and its manufacturing facility. Second, the per-lot quality testing items and whether the results are accessible. Third, the medical rationale for the injection site, dose, and number of sessions, along with an honest account of individual variability. Fourth, the protocol and compensation framework if adverse events occur. Fifth, the written terms for cancellation, refund, and carryover of unused sessions. A well-run clinic will take the time to answer all five. The willingness to speak plainly about indications and limits is what builds long-term trust in hair treatment.

Frequently Asked Questions

Q. Does a stem cell conditioned media hair treatment always need to be registered under the Regenerative Medicine Safety Act?

Because conditioned media contains no cells, its administration is, under the current interpretation, often considered outside the direct scope of the Act. However, the manufacturing process may fall under the designated cell processing facility registration, so confirming the facility’s registration status is meaningful. Because the regulatory landscape continues to evolve, checking the latest information is advisable.

Q. Is a treatment safe just because the ad says “MHLW-approved”?

Approval and registration are legally distinct, and the word “approved” in advertising is often used loosely to mean “registered.” Registration only signifies that the required documents have been submitted; it does not mean the government has guaranteed efficacy or safety. Precision of language often mirrors the posture of the clinic itself.

Q. Which risk class does conditioned media treatment fall under?

The prevailing interpretation is that cell-free conditioned media does not correspond directly to Classes I–III, though the framework continues to be debated. Rather than relying on classification alone, weigh the transparency of the manufacturing facility and the substance of quality testing.

Q. What specifically should I look for on a clinic’s website?

Check for clear statements on the cell source and manufacturing facility of the conditioned media, the lot-testing items performed, the response protocol for adverse events, and the terms for cancellation or refund. If only vague advertising language is present, ask direct questions at your first consultation.

Q. How should I judge a clinic that is reluctant to disclose information?

If a clinic pushes “special pricing” or “today-only offers” without producing concrete documentation, it is reasonable to pause and consider a second opinion. Reluctance to invest time in safety documentation tends to work against you in a long-term hair treatment.

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【Supervising Physician】Shin Moriwaki, MD

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

ECFMG Certificate

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📍AVAN TOKYO Ginza Hair Regenerative Medicine

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