June 2026 · refreshed monthly · 90 prompts across 4 assistants
When shoppers ask an AI assistant "Best vitamin C serum for brightening?", only a few vitamin c serum brands make the shortlist. In June 2026, across ChatGPT, Gemini, Perplexity and Amazon Rufus, Minimalist led with about 42% Share of AI, followed by Dot & Key and Plum. The single biggest driver of these recommendations was dermatologist & expert blogs. Here's the full leaderboard.
| # | Brand | ChatGPT | Gemini | Perplexity | Rufus | Share of AI | Trend |
|---|---|---|---|---|---|---|---|
| 1 | Minimalist | ● | ● | ● | ◐ | ▬ | |
| 2 | Dot & Key | ◐ | ● | ● | ● | ▲ 2 | |
| 3 | Plum | ◐ | ◐ | ● | ◐ | ▬ | |
| 4 | The Derma Co | ◐ | ● | ○ | ◐ | ▲ 2 | |
| 5 | Mamaearth | ◐ | ◐ | ◐ | ○ | ▼ 2 | |
| 6 | Garnier | ◐ | ○ | ○ | ◐ | ▼ 1 | |
| 7 | L'Oreal Paris | ◐ | ○ | ○ | ○ | ▼ 2 | |
| 8 | Pilgrim | ○ | ○ | ○ | ○ | ▼ 2 |
● frequently recommended ◐ sometimes ○ absent
The sources AI leans on when recommending vitamin c serum — this is where Share of AI is won or lost. Show up here and you show up in the answer.
▲ Gaining Share of AI
▼ Losing ground
We run about 90 representative buying prompts for vitamin c serum across ChatGPT, Gemini, Perplexity and Amazon Rufus, then measure how often and how prominently each brand appears, and which sources each assistant cites. Scores are comparable across brands and tracked month over month.
Expert blogs, research reports and infographics — practical, data-driven reading across e-commerce and quick-commerce.
Most fields are optional — the more you share, the better your sample.
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