Sunday Riley Good Genes: What the Brand Publishes, and the Number It Does Not
Good Genes is $85 for one fluid ounce — and $50, $122 or $205 depending on which of the four sizes you buy. The lactic acid is described in detail on every page. Its concentration is published on none of them.
★ Sizes and prices
- 0.5 fl oz (15 ml) — $50
- 1 fl oz (30 ml) — $85
- 1.7 fl oz (50 ml) — $122
- 3.4 fl oz (100 ml) — $205
- Lactic acid percentage: not published by Sunday Riley, Sephora or Ulta
The missing percentage
Sunday Riley describes the lactic acid as food-grade, biobased, vegan and sourced from France. It does not say how much of it is in the bottle. We checked the brand’s own page, Sephora and Ulta — none of them publishes a figure.
You will find “20% lactic acid” quoted in a lot of places online. We could not source it to the brand, so we are not repeating it. For an exfoliating acid, the concentration is the single most decision-relevant number there is, and its absence is worth noticing.
What is published about the formula
- Lactic acid — described as one of the most hydrating alpha hydroxy acids
- Licorice root, for brightening
- Lemongrass, described as astringent
- Arnica, for soothing
- Prickly pear extract, orchid, blue agave, aloe
- Squalane and caprylic/capric triglyceride for moisturisation
- Brand claims: sulfate-free, paraben-free, gluten-free, soy-free, phthalate-free, fragrance-free, vegan
How the brand says to use it
One to two pumps on clean, dry skin as a leave-on treatment, day or night. It can go on top of Luna Sleeping Night Oil and under moisturiser.
For sensitive skin, Sunday Riley gives different instructions: use it as a mask instead — one to three pumps on clean dry skin, left for 15 minutes, then removed. That is the brand telling you the standard leave-on use is not for everyone, which is a more useful caution than most acid products offer.
The cautions the brand publishes
Sunday Riley includes a medical note advising you to consult a physician or qualified healthcare provider about any medical condition or the use of skincare products, particularly during pregnancy or breastfeeding.
Standard AHA sense applies regardless: exfoliating acids increase photosensitivity, so daily sunscreen is not optional alongside them.
A note on the price you see quoted
$85 is correct for the 1 fl oz size only. Any page pairing $85 with a 1.7 oz bottle has the wrong number — that size is $122. Sephora also offers an Auto-Replenish price of $115.90 on the 1.7 oz.
Sources: Sunday Riley: Good Genes · Sephora listing · Ulta listing
How this was checked: figures on this page were read from the sources linked above on 26 August 2026. We have not tested this product ourselves; where a figure is the maker’s claim rather than an independent measurement, we say so. Prices change — check the retailer before buying. See our Editorial Policy.
