6 Anti-Aging Face Acids That’ll Transform Your Skin

Best for Dark Spots — Kojic Acid 

Years of UV exposure puts the production of melanin (skin’s pigment) into overdrive, resulting in brown patches that can worsen with each passing birthday. To erase them, Dr. Gohara points to kojic acid. “Derived from shiitake mushrooms and fermented rice, this acid inhibits tyrosinase, the enzyme responsible for producing pigment, to brighten spots for even-looking skin.” And unlike actual skin bleachers, kojic acid only targets the source, so it won’t lighten surrounding skin cells, ensuring skin remains uniform in tone.

TIP: Skin-lightening benefits can be rendered ineffective if exposed to sunlight, so opt for a kojic acid-infused night cream, like Reviva Labs Brown Spot Night Cream with Kojic Acid ($10.31, Amazon). Simply massage onto spots before bedtime to fade them in 6 to 8 weeks.

Best for Dull Skin — Glycolic Acid

Skin cell turnover, essential in leaving behind a youthful luster, slows with age. And when skin is sunburned, it further halts this natural shedding process, allowing dead, dull cells to build up on skin’s outer layer. Reveal a more glowing complexion with glycolic acid. The sugarcane derivative is a chemical exfoliant that gently sloughs away dead cells sans harsh scrubbing, says Hamden, Connecticut, dermatologist Mona Gohara, M.D. “That’s because the smaller molecules penetrate more quickly to dissolve the ‘glue’ that holds dead cells together.”

TO DO: Sweep a glycolic acid toner like Pixi Skin Treats Glow Tonic ($29, Target) onto clean skin twice a day for radiant skin in 30.

Best for Wrinkles — Ascorbic Acid 

Over time, a slow in skin-firming collagen and elastin production leads to a saggy, creased complexion made even worse after a summer in the skin-drying sun. But ascorbic acid (vitamin C in its most potent form) has been shown to accelerate the production of collagen and elastin to help reverse skin-aging, says Dr. Klein. “Plus, its antioxidants neutralize free radicals to shield against future damage.”

TIP: Liquid versions can quickly lose their potency, so try one in powder form to yield optimal results.

TO DO: Mix a pea-size amount of powder, like The Ordinary 100% L-Ascorbic Acid Powder, ($5.80, Skinstore.com), into a quarter-size dollop of your daily moisturizer (avoid use with ones containing niacinamide or retinol as the mix can cause irritation) for firmer, smoother skin in 12 weeks.

Best for Dyness — THIS Acid Mix

While hyaluronic acid has been the gold standard in acids that restore moisture to sun-parched, flaky skin (just 1 gram can hold up to 6 liters of water!), polyglutamic acid, a newly discovered soybean-derivative, has been found to lock up to four times as much moisture in skin cells as hyaluronic acid! Best of all? There’s no need to toss your hyaluronic acid-infused creams. Research shows that these acids work best when paired together. “Hyaluronic acid hydrates the lower levels of skin, while polyglutamic acid hydrates and plumps the top layer and then forms a protective barrier to lock all that moisture in,” says Dr. Klein. What’s more, polyglutamic acid has been found to thwart the enzymes that break down the natural hyaluronic acid in skin, increasing moisture levels even more over time.

TO DO: Mix a pea-size amount of polyglutamic acid, like The Inkey List Polyglutamic Acid, ($14.99, Sephora.com), into your hyaluronic acid-infused moisturizer, or use alone as the last step in your skincare routine. Use twice a day for soft, supple skin within 14 days.

Best for Rosacea — Azelaic Acid 

Sunlight, heat, spicy foods, alcoho l— the list of summer related indulgences that can trigger rosacea flare-ups goes on and on. The condition, typically marked by ruddy, bumpy patches of skin on the face, affects around 14 million of us. And since rosacea makes skin extremely sensitive, finding remedies that won’t further irritate skin can prove to be a challenging task. That’s where azelaic acid can help. Found in wheat, barley and rye, the super-gentle acid has anti-inflammatory properties that help reduce redness and calm irritation. Even better: “It acts as a keratolytic, an agent that removes the pores’ accumulation of keratin that can result in the raised, acne-like lesions characteristic of rosacea,” says Dr. Klein. Freeing up these blocked pores is key to improving skin texture, tone and clarity over time.

TO DO: Apply a pea-size amount of an azelaic acid treatment (like Paula’s Choice 10% Azelaic Acid Booster, $31 with coupon code FIRST15 at checkout, PaulasChoice.com) onto clean, dry skin (or add into your moisturizer) twice a day for relief within one week.

Best for Thinning Hair — Salicylic Acid

Months of increased sweating and humidity-induced oil can create a moist environment on the scalp that allows fungus to multiply, resulting in itchy dandruff. Scratching the infection inflames hair follicles and causes fallout while the resulting flakes clog scalp pores, stunting growth. The surprising solution? Salicylic acid! The same blemish-clearing properties of the acid we turned to all those years ago to combat teenage acne can actually restore a thicker head of hair, explains Dr. Gohara. Thanks to its ability to cut through oil and dirt on the scalp, the willow bark–derived acid dissolves the buildup that leads to the fungal infection, unclogging pores and preventing scalp- and hair-damaging itching. 

TO DO: Twice a week, swap your regular shampoo for one containing salicylic acid, like Neutrogena T/Sal Therapeutic Shampoo with Salicylic Acid, $7.79, Target, for a fuller, healthier mane in four weeks.

This story originally appeared in our print magazine. See more of our best product recommendations.

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