GHK-Cu in dollar store skincare: what the science says

What did @savewithjesnicole actually say?

The creator laid out a morning skincare sequence: cleanser, toner or essence (optional), vitamin C serum, hydrating serum like hyaluronic acid (for dry skin), moisturizer (optional depending on SPF), eye cream (optional), and finally SPF. She called SPF "the most important ingredient to use for anti-aging" and flagged vitamin C serum as "super important." The routine is geared toward an audience hunting dollar-store product swaps, not clinical-grade formulations.

To her credit, she qualified most steps as optional and matched product selection to skin type, which is more nuanced than the average TikTok skincare video. She did not make any disease-treatment claims, did not name specific doses, and kept the advice general enough to be broadly applicable.

Does the science back this up?

Mostly, yes. The layering order she describes follows the general rule of thinnest to thickest consistency, which is the consensus recommendation from dermatologists for maximizing ingredient penetration without physical interference between formulas.

On SPF: she is correct that it is the best-studied anti-aging intervention available without a prescription. A 2013 randomized controlled trial by Hughes et al. in the Annals of Internal Medicine found that daily broad-spectrum SPF 15 use over 4.5 years measurably reduced skin aging compared to discretionary use. That is real, hard data. Vitamin C (L-ascorbic acid) also has solid backing. A 2017 review by Pullar, Carr, and Vissers in Nutrients confirmed its role in collagen synthesis and UV-induced oxidative damage reduction, though stability in over-the-counter formulations varies considerably. Hyaluronic acid as a humectant is well-established for surface hydration, though it does not alter skin structure long-term (Bukhari et al., 2018, Molecules).

What did they get wrong (or right)?

The biggest miss is the eye cream recommendation. There is limited peer-reviewed evidence that eye creams outperform regular moisturizers for dark circles or puffiness in the general population. A 2022 review in the Journal of Cosmetic Dermatology noted that most eye cream ingredient concentrations are too low to produce measurable results, and that periorbital hyperpigmentation often has vascular or structural causes that topical products cannot address. Recommending eye cream for "smoother under-eye concealer application" is a cosmetic argument, not a clinical one, and that distinction matters.

She is right that toner is optional. The idea that toner is a necessary skin prep step is largely a marketing construct. Where she is also correct: telling people with oilier skin they can skip moisturizer if their SPF provides sufficient occlusion is reasonable advice, not reckless simplification. Some SPF formulations do provide adequate moisturization for non-dry skin types.

What should you actually know?

The layering sequence she describes is sound, but the effectiveness of any morning routine lives or dies by the quality of the individual products, not the order alone. A few things worth knowing:

• Vitamin C serums require L-ascorbic acid at pH below 3.5 and concentrations of 10-20% to be effective. Many dollar-store formulations do not meet these thresholds, and the creator's audience is specifically shopping dupes. That gap deserves more transparency.
• SPF needs to be applied as the final leave-on step before makeup, in sufficient quantity (approximately 1/4 teaspoon for the face) to reach labeled SPF values. Most people apply far less than tested amounts (Schalka and Reis, 2011, Anais Brasileiros de Dermatologia).
• Hyaluronic acid applied to dry air can pull moisture from the dermis rather than the environment, worsening dryness. Applying it to damp skin or following with an occlusive reduces this risk.
• Eye cream is optional in the way she says, but for a different reason than she implies. It is not that it is a luxury. It is that there is weak evidence it provides unique benefits beyond a well-formulated facial moisturizer.