Some outbound shop links may become affiliate links later. We will label them. Not medical advice.
K-beauty alternatives

Comparison · 25 August 2026 · Updated 26 August 2026 · prices move

Good Genes uses lactic acid. COSRX AHA 7 uses glycolic acid. That is a job match, not a dupe.

Sunday Riley Good Genes Lactic Acid Treatment is a leave-on exfoliating treatment built around purified lactic acid, licorice and a richer supporting formula. COSRX AHA 7 is a Korean liquid with 7% glycolic acid. Both address dullness and uneven texture, but the acid, vehicle and published formula are different.

Short version: We found no formula match. COSRX AHA 7 is the closest Korean AHA job match in this comparison because it publishes a defined glycolic-acid strength and targets the same broad exfoliation step. It does not copy Good Genes' lactic acid, supporting ingredients, texture or results.

What Good Genes actually is

ProductSunday Riley Good Genes Lactic Acid Treatment
FormatLeave-on lactic-acid treatment / serum
Standard size1 fl oz / 30 ml
Brand price$85 on the US product page
Published formula signalPurified lactic acid with licorice, botanical extracts, squalane and emollients; the current page does not publish a lactic-acid percentage
Availability checkedOfficial page showed out of stock on 25 August 2026

Good Genes is not just an “AHA serum” in the abstract. Sunday Riley names lactic acid as the exfoliating ingredient and describes the product as a treatment for the look of dullness, uneven tone and texture. The current official page also lists licorice, prickly pear, aloe, arnica, squalane and a silicone-and-emollient base. Because the brand does not publish a percentage on that page, we do not invent one from the phrase “high potency.”

Good Genes on Sunday Riley

Closest Korean job match: COSRX AHA 7

COSRX AHA 7 Whitehead Power Liquid

COSRX publishes a simpler and more measurable exfoliating brief: 7% glycolic acid in a 100 ml liquid. Its official INCI starts with apple fruit water and butylene glycol, followed by glycolic acid, niacinamide, panthenol and sodium hyaluronate. The list does not name lactic acid.

This makes COSRX a same-category, different-molecule job match. It is a relevant answer for someone searching for a lower-price Korean product for surface exfoliation, rough texture or whiteheads. It is not evidence that glycolic acid at 7% equals Good Genes, because Good Genes' lactic-acid percentage is not published here and the vehicles are different.

The COSRX US page listed a $22 regular price and showed no immediate stock when checked; a temporary $11 sale was also displayed in that snapshot. COSRX's official stores page lists YesStyle as an international authorized seller. The YesStyle US storefront showed 100 ml at about $17.60 on sale and in stock when checked, making it the practical purchase path to verify for country-specific shipping and price. Prices, promotions, shipping and eligibility move.

COSRX AHA 7 on COSRX COSRX AHA 7 on YesStyle

Side by side

Good Genes COSRX AHA 7
Lead acid Lactic acid Glycolic acid at 7%
Supporting formula Licorice, botanical extracts, squalane, silicones and emollients Apple fruit water, butylene glycol, niacinamide, panthenol and sodium hyaluronate
Format Serum-like leave-on treatment Water-based liquid exfoliant
Formula match? Original No — different AHA, vehicle and ingredient list
Job match? Original exfoliation / brightening step Yes — same broad exfoliation and texture job
Price checked 30 ml / $85 brand US 100 ml / $22 list price brand US; YesStyle snapshot about $17.60 sale and in stock

What “Korean alternative” does not prove

“AHA” is a family label, not a promise of identical performance. Lactic acid and glycolic acid are different acids; the concentration, pH, supporting ingredients and texture also shape how a product fits a routine. We therefore use job match for COSRX and reserve formula match for a materially closer ingredient-and-form comparison.

COSRX's official page advises introducing AHA 7 gradually and avoiding casual combinations with other acids, retinoids or vitamin C. Follow the product label, use sunscreen as directed, and stop if your skin reacts. This page is product comparison, not medical advice.

Related exfoliation comparisons

Different acids can serve a similar routine step without being interchangeable:

Sources