FDA warning letters on unapproved exosome and umbilical cord products

What happened in the US?

Between December 2024 and September 2025, the US Food and Drug Administration (FDA) sent warning letters to some US companies marketing exosome and umbilical cord-derived products. A warning letter is an official regulatory letter in which the FDA notifies a company in writing of the violations it has found; the FDA makes these letters public. The table below shows examples of these letters; it is not a complete list.

Exosomes are tiny vesicles released by cells, too small to be seen with the naked eye; they carry substances such as proteins and genetic material. The umbilical cord, the placenta, the amniotic membrane (the membrane that surrounds the baby in the womb) and the amniotic fluid inside this membrane are tissues and fluids related to pregnancy.

A letter concerning umbilical cord-derived products was reportedly also sent in February 2026; we could not verify this on the FDA’s own website.

What do the letters say?

In the letters we were able to read, the FDA describes exosome products as unapproved new drugs and unlicensed biological products under US law. Put simply, the FDA treats these products as drugs and biological products, and states that the approval or license required to market them in the US has not been obtained.

On its public web pages, the FDA also states that there is no approved exosome product in the US. In other words, the fact that a product is offered in the US under the name “exosome” does not mean that the FDA has reviewed and approved it.

The letters also cover products derived from umbilical cord, placenta and amnion. These products are not obtained from the recipient’s own tissue; in this respect, they differ from autologous procedures (prepared from the person’s own tissue). This difference does not mean that the evidence for autologous procedures is strong: as we explain on our autologous stem cell application page, the evidence for them is limited too.

What do the letters show, and what is not known?

Warning letters are not clinical studies or safety studies. They show that the FDA found these companies’ products to be in violation of the law; they do not measure how effective or how risky individual products are.

Some questions about this story also remain open:

• We could not confirm that any of the letters concerned a product offered for hair loss. This article is therefore not a verdict on any specific product used for hair loss.
• We could not verify every detail of the letters; here we report the information we were able to verify and point out separately what we could not.

The role of exosomes in hair loss is a separate question, and the evidence on it is limited too. As we explain on our exosome application page, much of what is known comes from laboratory and animal studies; there are few studies in humans, and they are small. There is also not yet a generally accepted standard for the content, purity and manufacturing conditions of exosome products.

The situation in Turkey

As of the date this article was written, we could not verify whether the Turkish Medicines and Medical Devices Agency (TITCK) has issued any decision or announcement on exosome products offered for hair loss. The FDA’s letters concern companies in the US and US law; they do not directly show the status of a product in Turkey.

This news does not mean that any exosome or umbilical cord product is, or is not, approved in Turkey.

What does this mean if you are considering a hair transplant or treatment?

Exosome or umbilical cord-derived products do not replace a hair transplant or treatment aimed at the cause of the hair loss. In a hair transplant, your own hair follicles are taken from the donor area (mostly the back and sides of the head) and placed in the thinning area; no hair follicles are transplanted with these products.

• During the examination, we first look at the cause of your hair loss, and you then discuss with your doctor which options suit you. Whether you are suitable for a hair transplant is determined during the examination; results also vary from person to person.
• If you are offered a supporting treatment, you can ask the clinic you are dealing with what the product is, what source it was obtained from, under what authorization it is used, what its possible risks are and what other options you have. Our article on questions to ask when choosing a clinic can also help.
• Do not obtain exosome or cell-derived products online or from abroad and use them on your own.
• If you have any unexpected symptoms after a procedure, contact the facility that carried it out or a healthcare facility.