The Short Version
The FDA regulates human cells, tissues, and cellular and tissue-based products, known as HCT/Ps, under a rule called 21 CFR Part 1271. There are two main pathways. A product that meets four specific criteria is regulated under Section 361, which requires registration and good tissue practices but not clinical trials or premarket approval. A product that fails any of those four criteria is regulated under Section 351 as a drug or biologic, which requires an Investigational New Drug application or full approval through a Biologics License Application. Intact adipose tissue that is only cryopreserved may qualify under Section 361. Enzyme-processed or culture-expanded cells generally do not and are considered investigational. Banking is preservation, not treatment, and it is not FDA-approved therapy. This page explains those pathways in plain language.
Important: This page is educational and explains how federal regulation works. It is not medical advice, not legal advice, and not a substitute for guidance from a licensed physician or attorney. SaveMyFat is a connector that links patients and providers with a U.S.-based tissue bank for adipose tissue banking. It does not collect, process, or store tissue itself, and it does not provide treatments or cures for any disease. Most adipose-derived cell products that are more than minimally manipulated are regulated as biologics and are not FDA-approved to diagnose, treat, cure, or prevent any disease. Regulations change; confirm current requirements with primary FDA sources and qualified counsel.
Why the Classification Question Matters
Almost every honest question about regenerative medicine comes back to one distinction: is a given product a Section 361 HCT/P or a Section 351 biologic? That single classification decides whether a product needs clinical trials and FDA approval before it can be marketed to treat disease, or whether it can be handled as minimally processed tissue under registration and good tissue practices. It is also the line that separates a lawful tissue preservation service from a clinic marketing an unapproved treatment.
This page walks through that framework in plain language: the four criteria that define a 361 HCT/P, what minimal manipulation and homologous use actually mean for adipose tissue, the registration and quality standards that apply, what FDA approval does and does not mean, and how state law layers on top of the federal rules. For a deeper background overview, see our companion article on understanding FDA regulations for adipose tissue. This page reflects the regulatory landscape as of July 2026 and is reviewed quarterly.
The 361 vs. 351 Classification, Explained
The FDA sorts regenerative medicine products into two primary pathways based on how the tissue is processed and what it is used for. Each pathway has distinct requirements that determine whether a product needs clinical trials and marketing approval. The table below summarizes the difference.
A product qualifies for the lighter Section 361 pathway only if it meets all four criteria in 21 CFR 1271.10(a): it is minimally manipulated; it is intended for homologous use only; it is not combined with another article, except water, saline, or certain preserving agents; and it either has no systemic effect and does not depend on the metabolic activity of living cells, or is intended for autologous use or use in first- or second-degree blood relatives. Fail any one of those, and the product is regulated as a 351 biologic that requires an IND or a BLA. Understanding which pathway applies helps patients tell the difference between legitimate tissue preservation and clinics marketing unapproved treatments that need, but lack, FDA approval.
The last two criteria are easy to overlook and often decide the outcome. A 361 product must not be combined with another article, apart from water, saline, or certain preserving agents, so adding scaffolds, growth factors, or drugs generally moves a product into biologic territory. And it must not have a systemic effect or depend on the metabolic activity of living cells for its primary function, unless it is for autologous use or for a first- or second-degree blood relative. Most cell therapies that are injected to act throughout the body, rather than to physically cushion or support tissue, run into this criterion and land in the 351 pathway.
Minimal Manipulation and Homologous Use
Two of the four criteria do most of the work in practice: minimal manipulation and homologous use. The FDA classifies adipose tissue as structural tissue, meaning its basic functions are cushioning, support, and insulation. Minimal manipulation means the processing does not alter the original characteristics of the tissue relating to those functions. According to the FDA’s 2017 guidance on minimal manipulation and homologous use, an HCT/P that is cryopreserved and stored generally meets the minimal manipulation criterion. This is why banking intact adipose tissue can fall under Section 361, while enzymatic isolation of stromal vascular fraction or culture expansion of adipose-derived cells is considered more than minimal manipulation and triggers the Section 351 pathway.
Homologous use means the tissue performs the same basic function in the recipient that it performed in the donor. Preserving adipose tissue for later structural use can be homologous. Using adipose-derived cells to treat a condition such as arthritis, a neurological disease, or an autoimmune disorder is generally non-homologous, which again pushes the product into the 351 pathway. We cover each of these in depth in what minimally manipulated really means under 1271 and homologous use, the 361 criterion physicians cannot ignore.
21 CFR Part 1271 and Establishment Registration
The entire framework lives in 21 CFR Part 1271, the federal regulation that governs how HCT/Ps are recovered, processed, stored, labeled, and distributed. Establishments that handle HCT/Ps must register with the FDA and list their products. It is important to be precise about what that means: registration is an administrative requirement, not an endorsement, and it does not mean the FDA has reviewed or approved any product. The FDA itself has warned consumers that FDA registration does not equal FDA approval.
Section 361 establishments must also make a donor eligibility determination through screening and testing, follow labeling requirements, and report adverse reactions and HCT/P deviations. For a fuller walkthrough, see what 21 CFR Part 1271 is and why it governs tissue and FDA establishment registration for HCT/P providers.
Current Good Tissue Practice (CGTP)
Current Good Tissue Practice, or CGTP, is the quality standard that governs the methods, facilities, and controls used to handle HCT/Ps. It covers every step: recovery, donor screening and testing, processing, storage, labeling, packaging, and distribution. The purpose is narrow and specific, which is to prevent the introduction, transmission, or spread of communicable disease. CGTP is the tissue-side counterpart to Current Good Manufacturing Practice (CGMP), which applies to 351 biologics.
Meeting CGTP is a compliance obligation, not a claim of clinical benefit. A lab can be fully CGTP-compliant and still offer only preservation, because CGTP governs how tissue is handled, not whether any future use is safe or effective. Our article on Current Good Tissue Practice and the FDA standard for labs goes deeper.
In practice, a compliant tissue bank builds several safeguards into the process. Pre-freeze viability testing establishes a baseline for each sample. Sterility testing confirms the absence of contamination. Continuous temperature monitoring with automated alarms keeps storage conditions stable. Chain-of-custody documentation and unique patient identifiers track every sample from collection through storage. None of these steps make banking a treatment. They exist so that, if a lawful future use ever applies, the stored tissue has been handled to a documented standard.
What "FDA Approved" Actually Means, and What It Does Not
FDA approved is a high bar. It means a product completed rigorous clinical trials demonstrating safety and effectiveness, received a Biologics License Application for biologics, and is authorized by the FDA for specific uses. As of 2026, the only FDA-approved stem cell products in the United States are blood-forming (hematopoietic) stem cells derived from umbilical cord blood, approved for certain blood disorders. Most conditions marketed by clinics, including arthritis, back pain, and neurological disease, have no FDA-approved stem cell treatment. You can read about the first approved mesenchymal product in the first FDA-approved mesenchymal stem cell product.
Enforcement makes the stakes real. The FDA and FTC have issued warning letters to regenerative medicine companies that marketed adipose-derived products with disease-treatment claims while failing to meet the Section 361 criteria, most often on minimal manipulation or homologous use. When a product is marketed to treat disease but has not filed an IND or obtained a BLA, it is an unapproved new drug. We summarize these patterns in FDA warning letters in regenerative medicine and the FTC stem cell enforcement pattern.
There are three lawful ways an investigational product reaches a patient, and none of them is a retail treatment. A registered clinical trial studies a product under an IND with informed consent and Institutional Review Board oversight. The FDA’s Expanded Access program, sometimes called compassionate use, can allow a seriously ill patient to receive an investigational product outside a trial when no comparable option exists and the FDA, the sponsor, and the treating physician all agree. Right to Try is a separate federal pathway with its own criteria that does not involve the FDA in the authorization step. All three are narrow, controlled, and case-by-case. Banking tissue does not enroll anyone in any of them.
How State Law Interacts With Federal Authority
Federal law is the floor, not the ceiling. Even when a product is handled correctly under 21 CFR Part 1271, states add their own rules on disclosure, consent, advertising, and who may perform or supervise procedures. Several states have passed stem cell specific laws. Florida’s SB 1768, Utah’s and California’s disclosure laws, Wyoming’s Stem Cell Freedom Act, and Nevada’s approach to unapproved biologics all illustrate how much the requirements vary by state.
For patients and physicians, the practical takeaway is that the federal classification is only the starting point, and the state where care happens can change what is required or permitted. See our multi-state stem cell law map for the overview, plus state-specific guides for Florida, Utah, Wyoming, California, and Nevada. A dedicated state stem cell law hub is in development.