Retinal vs. retinol: what Korean skincare TikTok gets right and wrong

What did @foreverwonyoungs actually say?

Here's the uncomfortable truth: the transcript for this video is essentially unusable. The auto-generated captions returned what appears to be garbled audio, song lyrics, and random numbers. There are no intelligible claims about retinal, Celimax, or Ksecret anywhere in the spoken content we can verify.

What we do have is the written caption, which states that Celimax Retinal Shot contains 0.1% retinal and is "great for anti-aging and tackling acne." The creator also expresses a personal preference for Celimax over Ksecret. Those caption claims are what we can actually evaluate. The video framing positions this as a head-to-head product comparison, which is a common and generally harmless format in skincare content, but it carries real responsibility when ingredient concentrations are named.

Does the science back this up?

The short answer is: retinal (retinaldehyde) has legitimate science behind it, and 0.1% is a real and studied concentration. But "great for acne" is doing a lot of work in that caption.

Retinaldehyde is the aldehyde form of vitamin A, sitting one oxidation step away from retinoic acid in the conversion chain. Unlike retinol, which requires two conversion steps, retinal requires only one, making it more potent per unit concentration. A randomized controlled trial by Sorg et al. (1999, Dermatology) found that 0.05% retinaldehyde performed comparably to 0.025% tretinoin in reducing fine lines over 18 weeks. More relevant to the acne claim, Pechere et al. (2002, Dermatology) found retinaldehyde had antimicrobial properties against Cutibacterium acnes in vitro, which is promising but not the same as a clinical acne cure. The concentration of 0.1% is on the higher end for over-the-counter retinal products and will cause purging and irritation in sensitive skin, a fact the caption omits entirely.

What did they get wrong (or right)?

Credit where it's due: calling retinal an anti-aging ingredient is accurate and supported by multiple studies. The 0.1% concentration claim for Celimax is verifiable from the product label and is consistent with what the brand advertises. Retinal is genuinely more potent than retinol at equivalent concentrations, so recommending it over retinol products is defensible.

What the caption gets wrong, or at least incomplete, is the acne claim. Retinoids do have a role in acne management, but the evidence for retinaldehyde specifically, as an over-the-counter topical at 0.1%, treating active acne is much thinner than the evidence for tretinoin or adapalene. Presenting it as simply "great for tackling acne" without nuance could lead someone with moderate-to-severe acne to delay seeking a prescription-strength retinoid or an antibiotic combination that actually has robust clinical backing. The comparison between Celimax and Ksecret also lacks any ingredient-level analysis in the caption, making the "fierce competition" framing feel more like preference content than an informed review.

What should you actually know?

If you are considering a retinal product, the concentration matters, but so does your baseline skin tolerance. Starting at 0.1% retinal without prior retinoid experience is a fast path to a compromised skin barrier, peeling, and the kind of purging that gets mistaken for a breakout. Most dermatologists who recommend retinal suggest starting at 0.025% to 0.05% and titrating up over several weeks.

The comparison between Korean OTC retinal products and prescription tretinoin is also worth addressing directly. Retinal requires enzymatic conversion to retinoic acid in the skin, and that conversion is variable between individuals. Tretinoin bypasses this step entirely. For anti-aging efficacy, the evidence base for tretinoin (Kligman et al., 1986, JAMA; Griffiths et al., 1995, NEJM) is substantially larger than for any OTC retinal product. That does not make retinal a bad choice, but it does mean the "just as good" framing some creators use is not supported.

• Retinal converts to retinoic acid in one step versus two for retinol, making it more efficient but also more irritating.
• Start low with any retinoid. The 0.1% concentration in Celimax is not a beginner formulation.
• The acne claim for retinal is biologically plausible but clinically understudied compared to prescription retinoids.
• Product preference comparisons without full ingredient breakdowns are entertainment, not medical guidance.