What It Is and How It Benefits Skin

If you've ever dealt with a stubborn dark spot or patch of discolored skin, then you know just how tough erasing hyperpigmentation can be. Fine lines and wrinkles may give away your age, but discoloration isn't exactly hiding it either. That's because skin that lacks a natural glow and even tone appears aged and weathered. The options are often few and far between when it comes to effective solutions for treating hard-to-get-rid-of hyperpigmentation that doesn't leave the skin dry, red or irritated.

For years, dermatologists relied on the skin-lightening powers of hydroquinone (as well as other ingredients). While many still prescribe it, a more natural alternative is giving hydroquinone a run for its money. Enter cysteamine, a proven skin brightener that improves discoloration across the board. From expert insight on how cysteamine works to how to use it and the best products with cysteamine, we're sharing everything you need to know about the under-the-radar skin brightener.

What Is Cysteamine?

Antioxidant-rich cysteamine is an amino acid derivative naturally found in the body that helps inhibit melanin production within the skin. In synthetic form, cysteamine is a safe and more tolerable way to treat hyperpigmentation and lighten discoloration compared to other ingredients and medications that have been go-tos for years.

Cysteamine was initially discovered in fish when scientists noticed a lightning effect. Although Corey L. Hartman, MD, says cysteamine has been around forever, it wasn't until recently that it made its way into topical skincare products. "Its pungent, sulfur-like scent was off-putting and hard to get past, but eventually, scientists developed it into a mask that is absorbed in a short-contact method, so you don't have to endure the smell on the skin for long (it dissipates when washed off the skin)."

Meet the expert

More skincare brands are beginning to formulate creams and serums with cysteamine; now that the skincare industry has learned that topical cysteamine doesn't require a doctor's prescription (it once did), it is becoming more mainstream. “It's increasingly popular due to its effectiveness at fading stubborn hyperpigmentation while still being a gentle alternative to harsher ingredients like hydroquinone,” Rachel Roff says.

Dendy Engelman, MD, says that because cysteamine is generally well-tolerated by a range of skin types, it is becoming a popular alternative to more harsh skin lightening and brightening agents such as hydroquinone. "Even though cysteamine is effective at reducing the excess pigment in the skin from various types of hyperpigmentation, including post-inflammatory hyperpigmentation (PIH), melasma and lentigines — thus returning hyperpigmented areas of the skin to their natural tone — it is also known to fight free radical damage in the skin, helping to slow down and prevent signs of premature aging," she says.

How Cysteamine Works

According to Roff, applying cysteamine topically to the skin helps to even out discoloration by reducing the amount of L-cystine, or cystine, in the skin. "By reducing cystine levels, cysteamine decreases the synthesis of melanin, thus helping combat dark spots and hyperpigmentation,” she says.

The science behind cysteamine and how it lightens areas of unwanted discoloration comes down to its functionality. "Cysteamine can do many things within the body's cells, including reducing copper and iron ions, increasing glutathione, and controlling melanin-producing tyrosinase,” she says. “These factors affect stubborn dark patches that develop on the skin."

But here's where cysteamine sets itself apart from other skin brighteners. Most can only improve certain types of discoloration, but Dr. Hartman says cysteamine works for all kinds of pigment—even stubborn, hormonally-induced melasma—and all skin tones and types, making it a more universally acceptable anti-pigment treatment. "Cysteamine even works well on skin that has a bit more melanin, which is prone to hyperpigmentation and wants to get their skin tone back to baseline without making it shades lighter," he says.

Cysteamine vs. Hydroquinone

Hydroquinone has been the go-to skin brightener for years, but all of that has changed with cysteamine's introduction. But that doesn't mean hydroquinone doesn't have a place in dermatologists' tool boxes — because it does, albeit a smaller one.

While Dr. Hartman says he still prescribes it here and there, he doesn't have his patients use nearly as much hydroquinone as they may have, and doesn't keep them on it for as long. "Some patients need hydroquinone, but most of the time, I prescribe cysteamine first to patients with hyperpigmentation. If the pigment is resistant to other therapies, or if they tried cysteamine or other pigment-reducing ingredients that didn't work, I'll have them use hydroquinone," he explains. "Years ago, I used to have patients start with hydroquinone to lighten hyperpigmentation, which I don't do anymore, but will move up to it if necessary."

There's always been a bit of skepticism from patients about using hydroquinone for several reasons, including potential toxicity and only being able to use the ingredient for limited periods. "Hydroquinone tends to cause a ‘halo effect’ around spots that have been treated with it, as it lightens all skin it comes into contact with,” Dr. Engelman says. “And it's not suitable for pregnant women, someone nursing, or anyone with vitiligo.”

Although hydroquinone is stronger than cysteamine, yielding faster results, she adds that one of the significant downsides to using it is that it can irritate the skin and cause dryness and redness — which is why she doesn’t recommend it for those with dry or sensitive skin. “Cysteamine, which can be purchased over the counter, is more gentle on the skin and usually well-tolerated by most skin types, especially those with sensitive or dry skin looking for a gentle yet effective solution to hyperpigmentation," she explains. "It also provides added antioxidant benefits, unlike hydroquinone." But for someone who wants to alleviate hyperpigmentation more quickly and whose skin can tolerate hydroquinone, that may be the right option for them.

Also, whereas hydroquinone is a bleaching agent, cysteamine isn't. "Cysteamine is a true pigment corrector, so it evens out the skin tone; it doesn't just lighten skin," Dr. Hartman shares. He calls cysteamine "completely nontoxic" and says it also works on various aspects of the melanin pathway, not just hydroquinone. But, for cysteamine to be effective, Dr. Hartman says it needs to be formulated at a concentration of at least five percent, which is the industry standard. "The only product I know of higher than five percent is the new version of Cyspera, which contains seven percent cysteamine."

How to Use Cysteamine

Cysteamine is not an apply-it-and-go ingredient that you can leave on the skin all day. Instead, it comes with specific instructions, so you'll need to carve out the dedicated time daily to use it correctly. While you can use cysteamine morning or night, it is effective when applied to unwashed skin (yes, even on dirty and makeup-laden skin). "When there is a little oil on the skin, cysteamine is less likely to be irritating," Dr. Hartman adds.

After applying a cream or serum that contains cysteamine, like Urban Skin Rx’s Hypercorrect Intense Fading Cream or Senté Cysteamine HSA, let it sit for 15 minutes before washing it off. Then, continue with your regular skincare routine. "You can also leave cysteamine on the skin for less than 15 minutes or dilute the strength by mixing it with a moisturizer if necessary," Roff says.  

The face isn't the only area where hard-to-erase discoloration likes to call home, and Roff says cysteamine can be used on other body parts, too, and even the lips. However, if you're using it to lighten dark spots on the lips, she says to leave it on the skin for five minutes at most for the first few weeks to ensure you don't irritate the skin.

Typically, cysteamine doesn't interfere with or counteract other skincare ingredients, including exfoliating acids and super potent actives. But Roff recommends caution and holding off on using other actives, such as retinol and exfoliators, just for the first few weeks. "Stick with just moisturizers and, of course, sunblock." Then, as the skin acclimates to the newly-introduced cysteamine, you can start slowly reintroducing other active ingredients into your skincare routine. If, for some reason, your skin appears irritated while using cysteamine, Roff says to give your skin a break for a few days, then start again.

When You’ll See Results

Cysteamine is effective in evening out the overall skin tone, but there won’t be a lightening effect. "The improvement isn't superfast, but it does even out the skin, so I think it's a more desirable outcome than just lightening the skin,” Dr. Hartman says. “More evenly-toned skin is the goal since people with hyperpigmentation usually don't want to fade or bleach their skin, but rather even it out.”  

Dr. Engleman says that with consistent use, cysteamine will fade hyperpigmentation over several weeks, noting, "Many patients notice a difference in about six to eight weeks, with optimal results at about 12 to 16 weeks." However, stubborn dark spots that have been there for a long time will take longer to fade. But once you see improvement, you can taper down using cysteamine twice weekly to maintain the results.

Of course, pairing cysteamine with in-office skin-brightening treatments helps amplify the results. Dr. Hartman likes using cysteamine with pico-second lasers, which break up pigment, and fractional resurfacing lasers or microneedling, which are also helpful for erasing discoloration. "Any time you combine a pigment-reducing ingredient with a professional treatment, the results will always be better than just the topical ingredient alone,” he says.

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