Which wellness supplement is everyone actually rebuying?

No real consensus this month on which ingredient is moving into genuine repeat-purchase territory. Despite 173 items across 10 sources, almost every cluster in the evidence is single-source (one Reddit thread, one Bilibili video, one YouTube interview) — there is no case where the same specific claim (e.g., "back on my third tub," a subscription mention, or a clear quit-story) is corroborated across multiple independent sources. What follows is the closest thing to a pattern, ranked by how much attention/engagement each got, not by cross-source agreement.

1. Creatine generates the most volume and debate, but it's polarized rather than consensus-repurchase. A high-engagement Reddit thread (539pts/216cmt) describes creatine "working wonders" for some and causing headaches/nausea for others, with commenters attributing side effects to hydration/electrolyte handling rather than the compound itself [1]. A separate, similarly popular Reddit thread (162pts/427cmt) asks directly about negative side effects [2], and a YouTube interview with Dr. Darren Candow makes an expert-driven case for creatine as a "health-span tool" for muscle, brain-stress recovery and possibly bone health, citing "120+ papers" [3]. (seen across 2 sources: Reddit, YouTube — but no shared specific claim, i.e. this is topic-level attention, not agreement on a fact)

2. Electrolytes are being actively re-evaluated for formulation, not repurchase loyalty. A pharmacist-style Reddit post questions whether electrolyte drinks need sugar and whether "sublingual electrolytes" are a real category [4], while a Bilibili video (13.5k views) walks through which electrolyte drink to choose [5]. Both are consumer-education/selection content — East Asia and North America converge on "how do I pick the right one" rather than testimony of repeat-buying. (seen across 2 sources: Reddit, Bilibili)

3. Magnesium content is split between selection guides and self-quantified experiments, with no repurchase evidence surfacing. Bilibili offers a ranked-food guide framing magnesium deficiency around cramping, poor sleep, and low mood [6], while Reddit has a "quantitative results" post on magnesium glycinate [7] — but neither includes subscription or repeat-tub language. (seen across 2 sources: Reddit, Bilibili)

4. Collagen is the most openly skeptical category, framed as an unresolved question rather than a repeat-buy staple. The top collagen thread is literally titled "Is collagen doing anything?" (133pts/250cmt on r/Supplements) [8] — high engagement, but the framing itself signals doubt rather than loyalty, and no repurchase or subscription language appears in the evidence provided. (seen across 1 source: Reddit — thin, single-source)

5. Adaptogens are essentially absent from the firsthand evidence. No dedicated cluster, repurchase story, scepticism thread, or Xiaohongshu/Weibo note about adaptogens appears despite Xiaohongshu having 39 items and Weibo having 1 item logged for this cycle — suggesting either low volume this month or the topic wasn't surfaced by these agents' queries.

Regional note: the only clear East Asia signal (Bilibili, Xiaohongshu, Weibo) leans toward practical "which product to choose" and food-based guidance for magnesium/electrolytes, while North American/Reddit-YouTube content skews toward personal experimentation, side-effect debate, and expert validation for creatine and collagen. This is a difference in content genre, not a stated disagreement on efficacy — the evidence doesn't show East Asian and Western communities directly contradicting each other on any single ingredient.

Honest caveat: the input is thin for this specific ask. Almost nothing in the given evidence contains explicit repurchase phrases ("third tub," subscription renewal) or quitting narratives with reasons — the raw findings are dominated by single-source clusters and general question/skepticism threads, so a stronger repurchase-vs-scepticism comparison isn't supportable from what's here.