Citric Acid Is the Underrated AHA That Deserves Our Attention

We don't like to play favorites, but when it comes to skincare acids, alpha-hydroxy acids (or AHAs) might take the cake. It's not that we don't love the deep clean from a salicylic acid, but nothing delivers an instant glow-up quite like an AHA—and boy, are there plenty of them to choose from. You may be familiar with glycolic acid already, but citric acid has some unique properties and good-for-your-skin benefits that set it apart.

Ahead, experts Gretchen Frieling, Ife J. Rodney, and David Petrillo, explain what makes citric acid so special, as well as why and how to incorporate it into your skincare routine. Read on for everything you need to know about how citric acid benefits your skin.

What Is Citric Acid?

"Citric acid is a type of alpha-hydroxy acid that's extracted from citrus fruits such as lemons, limes, oranges, and grapefruits, as well as other fruits such as berries," explains Rodney. It's also an incredibly common ingredient, plentiful not only in many types of skincare but also things such as food and household cleaners, and is even used as a preservative, she adds.

Benefits of Citric Acid for Skin

Because it is an AHA, citric acid offers the same types of exfoliating properties as any AHA would. But it also has a few additional benefits worth calling out.

• Acts as a chemical exfoliant: All alpha-hydroxy acids, citric acid included, work by helping to dissolve the "glue" that keeps dead cells stuck together on the surface of the skin. By promoting cell turnover and helping these dead cells slough off, it helps unclog pores, even out skin tone, and improve overall textures, says Frieling.
• Easily tolerated: What separates citric acid the most from other AHAs is its larger molecular size, making it difficult for the skin to absorb. While this reduces its potency, it does make it a gentler alternative for those with sensitive skin.
• Has astringent properties: Oily skin types, take note. Citric acid is a natural astringent, helping to dry out excess oil and leaving the skin feeling nice and clean, notes Rodney.
• Contains protective antioxidants: "Citric acid is unique compared to other acids because it also has antioxidant benefits," says Frieling. "External aggressors, such as sun damage, can wreak havoc on skin cells. Antioxidants like citric acid can help combat some of that oxidative stress to reveal brighter-looking skin."
• Helps maintain the skin's pH levels: Here's another unique feature. "With a natural pH of about 2, citric acid is an excellent pH balancer," notes Rodney. Why is that important? Keeping the skin's pH from becoming too alkaline helps maintain normal skin barrier function, explains Frieling. A well-functioning skin barrier is at the root of healthy, beautiful skin.

Citric Acid vs. Glycolic Acid

Both citric acid and glycolic acid are members of the alpha-hydroxy acid (AHA) family, though glycolic acid may get considerably more airtime. Similar to all AHAs, both work to slough away dead skin cells from the top layer of skin. The main difference is at the molecular level. "Citric acid's molecules are larger than those of glycolic acid, which is the smallest of all the AHAs," explains Petrillo. That means that it's harder for the skin to absorb the citric acid, which means it's weaker and less potent. But the upshot is that it may be much easier for someone to tolerate citric acid than it would be glycolic acid, Petrillo adds.

Citric Acid vs. Lactic Acid

Lactic acid is another alpha-hydroxy acid that shows up in many exfoliating skincare products. Unlike citric acid, which is sourced from citrus fruits and berries, lactic acid is produced from sour or fermented dairy products. (It's also produced by the body to fuel muscles during a difficult workout.) Like most AHAs, both citric and lactic acid buff away the outer layer of the skin for a smoother appearance, but their molecular differences affect deeper penetration. "[Citric acids] are also bigger than lactic acid, pyruvic acid, and tartaric acid," explains Petrillo. Lactic acid has a larger molecular size than glycolic acid, but is smaller than a molecule of citric acid. This makes lactic acid more easily absorbed by the skin, and more potent than citric acid. While both lactic and citric acids are gentler than glycolic, citric acid would be the most tolerable and gentle for those with skin sensitivities—especially considering its additional skin-balancing properties courtesy of the lower pH.

Potential Side Effects of Citric Acid for Skin

While citric acid is considered gentler and more mild than others, it is still an acid, which means there's always some potential for irritation. This holds especially true for those with sensitive skin or an inflammatory skin condition, such as rosacea, notes Petrillo.

How to Use Citric Acid for Skin

As is the case with many other acids, the experts we spoke with agree that it's best to follow particular product directions for application and usage. Citric acid is often paired with other acids—both AHAs and BHAs—because they all work together synergistically, but proceed with caution if you have sensitive skin. And avoid using any kind of physical exfoliant, such as a scrub or abrasive tools, at the same time, notes Petrillo. Similarly, if a retinoid is part of your skincare regimen, don't use it at the same time as citric acid. Use the citric acid in the morning and the retinoid at night, or alternate days.

The Final Takeaway

There's no shortage of alpha-hydroxy acids in the skincare world. And while glycolic and lactic acid often get all the attention, citric acid deserves equal consideration. It's a far gentler member of the AHA family that still delivers the same exfoliating benefits for exceptionally smooth, glowing skin. Plus, its citrusy origins offer exclusive antioxidant qualities that protect from sun damage and oxidative stress.