Check which GRO formula you are reading about
The current US GRO page lists named peptide ingredients alongside botanicals. Older descriptions that call every GRO formula peptide-free are therefore an unreliable shortcut. Even so, the checked formula does not list Copper Tripeptide-1, which Divi does.
Both formulas include aromatic ingredients. GRO also lists denatured alcohol, whereas the checked Divi list does not. Use your established ingredient preferences rather than assuming either brand is universally suitable for a sensitive scalp.
Study headlines need their methods
Both brands publish consumer-perception findings. Their durations and sample sizes differ. Those results do not provide a direct comparison of the formulas, and a higher survey percentage from one brand does not establish a better product.
A proper head-to-head claim would require the same measurement and an appropriate study design. We do not turn unrelated surveys into a comparative score.
Our decision rule
Use copper content as the first decision if it is central to your brief. Otherwise compare the full formula, ordinary total and subscription cancellation terms. Choosing a recurring offer should follow experience with the routine rather than be driven by a first-order discount.
Sources & further reading
Product pages establish brand claims and label facts. They do not independently validate efficacy. Sources checked 14 September 2026.
- Divi: Scalp Serum — official product and ingredients
- Vegamour: GRO Hair Serum — official product and ingredients
- 2023 primary study: GHK-Cu delivery in ionic liquid microemulsions