Hanasui Body Spa Exfoliating Gel Coffee

Because lactic acid molecules are larger than glycolic acid, they don’t penetrate as deeply. This means they’re less likely to sting or irritate, making it a great choice for beginners or those with sensitive skin.

Like glycolic acid, it can:

Lactic acid also acts as a humectant (like hyaluronic acid). It can draw water into the skin to improve hydration and also plays a role in the skin's natural moisturizing factor (NMF) in the form of sodium lactate.

Studies show it can boost ceramide production to strengthen the skin barrier and even help balance the skin’s microbiome.

To get results, choose products with a pH between 3-4.

Lower strengths (5-12%) focus on surface exfoliation; higher strengths (12% and up) can reach deeper in the dermis (deeper, supportive layer) to improve skin texture and firmness over time.

Though it was originally derived from milk, most modern lactic acid used in skincare is vegan. It is made through non-dairy fermentation to create a bio-identical and stable form suitable for all formulations.

When lactic acid shows up near the end of an ingredient list, it usually means the brand added just a tiny amount to adjust the product’s pH.

Legend has it that Cleopatra used to bathe in sour milk to help reduce wrinkles.

Lactic acid is truly a gentle multitasker: it exfoliates, hydrates, strengthens, and brightens. It's a great ingredient for giving your skin a smooth, glowing, and healthy look without the harshness of stronger acids.

Read more about some other popular AHA's here:

The CIR Expert Panel has confirmed this ingredient to be nontoxic and clinical studies show no sensitization at cosmetic use concentrations.

True allergic reactions are quite rare: a 15-year retrospective study of 6,751 patients found only 0.31% had a positive reaction (and less than half were considered clinically relevant).

It seemed that when sensitization does occur, it's most commonly linked to topical medication (like corticosteroids) and not cosmetics. Allergic contact dermatitis also appears largely limited to individuals with underlying skin conditions.

Overall, propylene glycol is a well-studied ingredient that most people can tolerate without issue.

A high amount of carbomer can cause pilling or balling up of products. Don't worry, most products contain 1% or less of carbomer.

Emollients help soothe and soften the skin. They do this by creating a protective film on your skin. This barrier helps trap moisture and keeps your skin hydrated. Emollients may be effective at treating dry or itchy skin.

This ingredient may or may not be vegan, depending on the source.

Peg-40 Hydrogenated Castor Oil may not be fungal-acne safe. We recommend speaking with a professional if you have any questions or concerns.

Biologically, collagen is responsible for keeping skin firm and youthful. Collagen is comprised mostly of glycine, proline, and hydroxypoline. These are amino acids.

Collagen will not increase sun sensitivity, but you should always wear sunscreen during the day.

Learn more about hydrolyzed collagen here.

It also contains sugars in the form of monosaccharides and polysaccharides, folic acid, choline, many common minerals such as calcium, 12 anthraquinones, fatty acids, amino acids, and Vitamin B12.

The polysaccharides in aloe help moisturize your skin.

Despite helping with sunburn, aloe should not replace your sunscreen.

Vaccinium Myrtillus Fruit Extract also helps reduce irritation.

Research shows it can encourage your skin cells to turn over and renew by stimulating keratinocyte and fibroblast proliferation.

It also has mild keratolytic properties to help loosen and shed dead skin cells without being harsh.

Studies also suggest allantoin can help calm inflammation by dialing down some of the chemical signals your skin sends out when it is irritated.

This ingredient is typically used in the 0.1-0.5% range, and the FDA recognizes it as a skin protectant in OTC products up to 2%.

Overall, allantoin is a wonderful addition to most routines; it is stable across a wide pH range (~4-8), works well with other ingredients, and is considered non-sensitizing/non-irritating.

Fun fact: Allantoin is naturally occurring in comfrey root, beets, chamomile, and wheat sprouts. Our bodies even produce it as a byproduct of uric acid metabolism.

For instance, Habanolide is a proprietary trade name for a specific aroma chemical. When used as a fragrance ingredient in cosmetics, most aroma chemicals fall under the broad labeling category of “FRAGRANCE” or “PARFUM” according to EU and US regulations.

The term 'parfum' or 'fragrance' is not regulated in many countries. In many cases, it is up to the brand to define this term.

For instance, many brands choose to label themselves as "fragrance-free" because they are not using synthetic fragrances. However, their products may still contain ingredients such as essential oils that are considered a fragrance by INCI standards.

One example is Calendula flower extract. Calendula is an essential oil that still imparts a scent or 'fragrance'.

Depending on the blend, the ingredients in the mixture can cause allergies and sensitivities on the skin. Some ingredients that are known EU allergens include linalool and citronellol.

Parfum can also be used to mask or cover an unpleasant scent.

The bottom line is: not all fragrances/parfum/ingredients are created equally. If you are worried about fragrances, we recommend taking a closer look at an ingredient. And of course, we always recommend speaking with a professional.

The FDA requires batch-to-batch certification for this ingredient that is held to a pretty rigorous standard. That means the CI 17200 in your cosmetics has been tested and approved before it ever reaches you.

Contact allergy to cosmetic-grade dyes used at low concentrations are uncommon but has been documented before.

This ingredient also goes by the name D&C RED NO. 33.

CI 17200 has a comedogenic rating of 1 and an irritancy rating of 2 on a scale of 0-5. This is based on peer-reviewed research from the man who invented the comedogenic scale.

A 1 on the comedogenic scale is about as low as it gets without being a flat zero, and makes sense for CI 17200.

It's a water-soluble dye used at very small concentrations (typically 0.001-0.1%), so it dissolves into the water phase of a formula rather than sitting on your skin the way an oil or wax would.

The irritancy rating of 2 reflects that, like most synthetic dyes, there's a small possibility of mild irritation ( particularly for people with existing dye sensitivities).

For the vast majority of people, it's a non-issue at typical use levels.

It's also worth keeping in mind that comedogenic and irritancy ratings are tested on individual ingredients, not finished formulas. The final product's formulation, concentration, and other ingredients all play a role in how something actually behaves on your skin.

Just so you know, the FDA ban on Red Dye No. 3 refers to CI 45430, not this ingredient. CI 45430 and CI 17200 are different chemical compounds with distinct safety and regulatory histories.

It's also worth noting that Red No. 3 (CI 45430) was already banned from cosmetics back in 1990, so the 2025 action just extended the ban to food and oral drugs. CI 17200 was never part of any of this.