The beauty market abounds with high-end creams and serums that claim the use of stem cells to rejuvenate aging skin.

Selling on the internet and at department stores like Nordstrom, these products promise "breakthrough" applications to plump, smooth, and "reverse visible signs of aging," and at least one product offers to create a "regenerative firming serum, moisturizer, and eye cream" from customers' own stem cells – for a whopping $1200.

The beauty industry is heavily hyping glimmers of the nascent field of stem cell therapy.

Steeped in clinical-sounding terms like "proteins and peptides from pluripotent stem cells," the marketing of these products evokes a dramatic restoration of youthfulness based on cutting-edge science. But the beauty industry is heavily hyping glimmers of the nascent field of stem cell therapy. So what is real and what's not? And is there in fact a way to harness the potential of stem cells in the service of beauty?

Plant vs. Human Stem Cells

Stem cells do indeed have tremendous promise for treating a wide range of diseases and conditions. The cells come from early-stage embryos or, more commonly, from umbilical cord blood or our own bodies. Embryonic stem cells are considered the body's "master" cells because they can develop into any of our several hundred cell types. Adult stem cells, on the other hand, reside in mature tissues and organs like the brain, bone marrow, and skin, and their versatility is more limited. As an internal repair system for many tissue types, they replenish sick, injured, and worn-out cells.

Nowadays, with some sophisticated chemical coaxing, adult stem cells can be returned to an embryonic-like blank state, with the ability to become any cell type that the body might need.

Beauty product manufacturers convey in their advertising that the rejuvenating power of these cells could hold the key to the fountain of youth. But there's something the manufacturers don't always tell you: their products do not typically use human stem cells.

"The whole concept of stem cells is intriguing to the public," says Tamara Griffiths, a consultant dermatologist for the British Skin Foundation. "But what these products contain is plant stem cells and, more commonly, chemicals that have been derived from plant stem cells."

The plant stem cells are cultured in the lab with special media to get them to produce signaling proteins and peptides, like cytokines and chemokines. These have been shown to be good for reducing inflammation and promoting healthy cell functioning, even if derived from plants. However, according to Griffiths, there are so many active ingredients in these products that it's hard to say just what role each one of them plays. We do know that their ability to replenish human stem cells is extremely limited, and the effects of plant stem cells on human cells are unproven.

"...any cosmetic that is advertised to be anti-aging due to plant stem cells at this time is about as effective as all the skin creams without stem cells."

Whether products containing plant cell-derived ingredients work better than conventional skin products is unknown because these products are not regulated by the U.S. Food and Drug Administration and may rest on dubious, even more or less nonexistent, research. Cosmetics companies have conducted most of the research and the exact formulas they devise are considered proprietary information. They have no incentive to publish their research findings, and they don't have to meet standards imposed by the FDA unless they start using human cells in their products.

"There are biological limits to what you can do with plant cells in the first place," says Griffiths. "No plant stem cell is going to morph into a human skin cell no matter what magic medium you immerse it in. Nor is a plant cell likely to stimulate the production of human stem cells if applied to the skin."

According to Sarah Baucus, a cell biologist, for any type of stem cell to be of any use whatsoever, the cells must be alive. The processing needed to incorporate living cells into any type of cream or serum would inevitably kill them, rendering them useless. The splashy marketing of these products suggests that results may be drastic, but none of these creams is likely to produce the kind of rejuvenating effect that would be on par with a facelift or several other surgical or dermatological procedures.

"Plant stem cell therapy needs to move in the right direction to implement its inherent potential in skin care," researchers wrote in a 2017 paper in the journal Future Science OA. "This might happen in the next 20 years but any cosmetic that is advertised to be anti-aging due to plant stem cells at this time is about as effective as all the skin creams without stem cells."

From Beauty Counter to Doctor's Clinic

Where do you turn if you still want to harness the power of stem cells to reinvigorate the skin? Is there a legitimate treatment using human cells? The answer is possibly, but for that you have to switch from the Nordstrom cosmetics counter to a clinic with a lab, where plastic surgeons work with specialists who culture and manipulate living cells.

Plastic surgeons are experts in wound healing, a process in which stem cells play a prominent role. Doctors have long used the technique of taking fat from the body and injecting it into hollowed-out or depressed areas of the face to fill in injuries, correct wrinkles, and improve the face's curvature. Lipotransfer, or the harvesting of body fat and injecting it into the face, has been around for many years in traditional plastic surgery clinics. In recent years, some plastic surgeons have started to cull stem cells from fat. One procedure that does just that is called cell-assisted lipotransfer, or CAL.

In CAL, adipose tissue, or fat, is harvested by liposuction, usually from the lower abdomen. Fat contains stem cells that can differentiate into several cell types, including skin, muscle, cartilage, and bone. Fat tissue has an especially stem cell-rich layer. These cells are then mixed with some regular fat, making in effect a very stem cell-rich fat solution, right in the doctor's office. The process of manipulating the fat cells takes about 90 to 110 minutes, and then the solution is ready to be injected into the skin, to fill in the lips, the cheeks, and the nasolabial folds, or the deep folds around the nose and mouth.

Unlike regular fat, which is often injected into the face, some experts claim that the cell-enriched fat has better, longer-lasting results. The tissue graft grows its own blood vessels, an advantage that may lead to a more long-lasting graft – though the research is mixed, with some studies showing they do and other studies showing the complete opposite.

For almost all stem cell products on the market today in the U.S., it is not yet known whether they are safe or effective, despite how they are marketed.

One of the pioneers in CAL, a plastic surgeon in Brazil named Dr. Aris Sterodimas, says that the stem cells secrete growth factors that rejuvenate the skin -- like the plant stem cells that are used in topical creams and serums. Except that these cells are human stem cells and hence have inherently more potential in the human body.

Note that CAL doesn't actually result in large numbers of fresh, new replacement cells, as might be imagined. It's simply fat tissue treated to make it richer in stem cells, to have more of the growth-inducing proteins and peptides delivered to the dermis layer of the skin.

Sterodimas works alongside a tissue engineer to provide CAL in his clinic. He uses it as a way to rebuild soft tissues in people disfigured by accidents or diseases, or who are suffering the after-effects of radiation treatments for cancer.

Plastic surgeons get plenty of these patients. But how widespread is CAL for beauty purposes? Sterodimas says that he regularly performs the procedure for Brazilians, and it's widely available in Europe and Japan. In the U.S., the procedure hasn't taken off because there is no FDA approval for the various methods used by different doctors and clinics. A few major academic centers in the U.S. offer the treatment on a clinical trials basis and there are several trials ongoing.

But there is a downside to all lipotransfers: the transplanted fat will eventually be absorbed by the body. Even the cell-enriched fat has a limited lifespan before reabsorption. That means if you like the cosmetic results of CAL, you'll have to repeat the treatment about every two years to maintain the plumping, firming, and smoothing effects on the skin. The results of CAL are "superior to the results of laser treatments and other plastic surgery interventions, though the effect is not as dramatic as a facelift," says Sterodimas.

Buyer Beware

For almost all stem cell products on the market today in the U.S., it is not yet known whether they are safe or effective, despite how they are marketed. There are around 700 clinics in the U.S. offering stem cell treatments and up to 20,000 people have received these therapies. However, the only FDA-approved stem cell treatments use cells from bone marrow or cord blood to treat cancers of the blood and bone marrow. Safety concerns have prompted the FDA to announce increased oversight of stem cell clinics.

As for CAL, most of the clinical trials so far have been focused on using it for breast reconstruction after mastectomy, and results are mixed. Experts warn that the procedure has yet to be proven safe as well as effective. It's important to remember that this newborn science is in the early stages of research.

One question that has also not been definitively settled is whether the transplanted stem cells may give rise to tumors — a risk that is ever-present any time stem cells are used. More research is required to assess the long-term safety and effectiveness of these treatments.

Given the lack of uniform industry standards, one can easily end up at a clinic that overpromises what it can deliver.

In the journal Plastic Reconstruction Surgery in 2014, Adrian McArdle and a team of Stanford University plastic surgeons examined the common claims of CAL's "stem cell facelifts" being offered by clinics across the world. McArdle and his team write: "…the marketplace is characterized by direct-to-consumer corporate medicine strategies that are characterized by unsubstantiated, and sometimes fraudulent claims, that put our patients at risk." Given the lack of uniform industry standards, one can easily end up at a clinic that overpromises what it can deliver.

But according to McArdle, further research on CAL, including clinical trials, is proceeding apace. It's possible that as more research on the potential of stem cells accrues, many of the technical hurdles will be crossed.

If you decide to try CAL in a research or clinical setting, be forewarned. You will be taking part in a young science, with many unknown questions. However, the next time someone offers to sell you stem cells in a jar, you'll know what you're paying for.