After interviewing Kathy Macdonald about Luka Cosmetics, the mineral makeup range that she developed, I reflected on what she said were the key anti-aging ingredients she incorporated into her formulas. There were many familiar faces, including aloe, vitamins A and E, and copper peptides. Kathy also sought out popular peptides like palmitoyl tripeptide, one half of what makes up Matrixyl 3000, and palmitoyl tripeptide-5, both known to stimulate collagen synthesis in the skin. The one ingredient Kathy mentioned that gave me pause was manganese. I knew that manganese is a natural mineral, like copper, but had never heard about its benefits in skin care. Once my curiosity got the better of me, I started digging deeper.

Manganese is a mineral present in large quantities in plants and animals. Only trace amounts of this element (roughly 20 milligrams) can be found in the human body, predominantly in the bones, kidney, liver, and pancreas. Manganese acts as a coenzyme that facilitates numerous metabolic processes in the body. The formation of connective tissue, bones, and sex hormones, as well as calcium absorption and blood sugar regulation all rely on manganese.

To keep these vital functions running smoothly, it’s important to take in manganese through daily nutrition. Luckily, it is abundant in natural sources, including broccoli, beans, seeds, whole grains, egg yolks, avocados, seaweeds, spinach, and nuts (literally, from soup to nuts). Manganese helps the body absorb vitamin B and vitamin E, and it works in tandem with B-complex vitamins to combat depression, anxiety, and mood disorders. Low levels of manganese can lead to health problems like joint pain, arthritis, diabetes, osteoporosis, infertility, and epilepsy. Despite the prevalence of manganese in leafy vegetables and legumes (which should be part of anyone’s diet), supplements are sometimes recommended to avoid manganese deficiency.

One popular supplement is manganese gluconate, a salt of manganese and gluconic acid. As an oral supplement, it is marketed to aid energy production, thyroid function, and bone development. It is a popular supplement among athletes on high-protein diets, since excess protein can deplete minerals such as manganese. So what does it have to do with skin care?

At some point in the past decade or so, manganese gluconate entered the realm of cosmetics. Hailed as an antioxidant that moonlights as a wrinkle smoother, manganese gluconate became the anti-aging ingredient du jour in the early aughts. Lancome launched its D-Contraxol line featuring manganese gluconate as the star ingredient. Lancome’s Concentrated Anti-Wrinkle Essence promises to “correct existing wrinkles with its unprecedented action on facial skin contractions... preventing future wrinkles by reinforcing the resistance of deep skin layers,” all through the action of one active ingredient. Can manganese gluconate really relax facial contractions at the cellular level as Lancome proclaims?

In 2003, a Wall Street Journal reporter took Lancome’s Resolution D-Contraxol for a test drive and concluded her one-month trial with a slightly more shallow furrow between her eyebrows. A top Manhattan dermatologist who she consulted was even taken aback by the results. A representative of parent company L’Oreal explained this effect as the work of a “mineral called manganese gluconate, which sends a signal to the skin’s fibroblast cells to relax, reversing expression lines.” It reportedly took a full decade of lab work and clinical trials to arrive at D-Contraxol’s magical formula. Extensive manufacturer-sponsored testing found that D-Contraxol helps smooth fine lines caused by smiling, frowning, and other facial movements.

The results of these private studies are nowhere to be found online; thus, making any hard evidence for manganese gluconate’s power over wrinkles unavailable to the general public. Interestingly, that same WSJ reporter also tested Wrinkle De-Crease from L’Oreal Paris (which similarly relies on the mineral manganese as its secret sauce) several months later, by which point her furrowed brow had returned to its original state. The result? Neither she nor her dermatologist noticed any difference in that stubborn wrinkle.

Though manganese gluconate might have an effect on the body as a nutritional supplement, there is no published, peer-reviewed proof that it serves any purpose when applied to the skin, aside from possible antioxidant benefits. To think that this mineral can magically relax fibroblasts (the cells that create collagen) is preposterous. Unless you immobilize targeted muscles, they will inevitably contract as your face flexes to make expressions. Though L’Oreal’s dog and pony show to make manganese gluconate behave like Botox was misguided, the company is not alone. Other cosmetics manufacturers have jumped on the manganese gluconate bandwagon, despite the lack of evidence that this mineral is anything more than an antioxidant. Ole Henriksen’s truth serum, for instance, may not be exactly truthful in claiming to boost collagen through manganese gluconate.

However, all hope is not lost for manganese in skin care. Manganese is a key component of manganese superoxide dismutase (MnSOD), one of three major superoxide dismutase enzymes (along with copper-zinc superoxide dismutase and extracellular superoxide dismutase) within the human cell. As the only antioxidant enzyme localized in the mitochondrial matrix, MnSOD has several essential biological functions and, as this medical journal describes in detail, it even has the power to suppress tumors.

Most pertinent to skin care, MnSOD neutralizes free radicals. These damaging particles can damage cell membranes, mess with genetic material, and contribute to the aging process. A 2011 study on mice at the University of Kentucky’s Graduate Center for Toxicology found that MnSOD had a critical role in preventing mitochondrial DNA damage caused by exposure to UVB radiation. This study, along with similar studies, proves that MnSOD is a powerful antioxidant that can protect the cells from oxidative stress and photoaging.

Manganese superoxide dismutase may reduce, or even prevent, damage caused by free radicals. As such, it is an excellent addition to an anti-aging ingredient arsenal. But in the form of manganese gluconate, there is no scientific support for topical benefits. All in all, the use of manganese in cosmetics comes with caveats.