The State of Supplement Stacking
We mapped 200 supplements, 161 interaction pairs, and 87 timing guides into one evidence-graded dataset, backed by 71,776 randomized trials, meta-analyses and systematic reviews indexed on PubMed. Here is what it shows about what is redundant, what to never combine, when to take things, and the nutrients linked to the most symptoms. Free to cite with a link.
Most supplement pairs people worry about do interact, but rarely dangerously.
Of the 161 common supplement pairs we mapped, only 17 (11%) warrant real caution. Far more often the issue is money or timing, not safety: 16 pairs are redundant (you are paying twice for the same effect) and 10 simply need to be spaced apart.
16 pairs are redundant. People routinely pay twice for the same effect.
The most common waste in a stack is buying two things that do the same job. A sample of the redundant pairs in the dataset:
The combinations that actually need caution cluster around bleeding and serotonin.
The 17 caution pairs are dominated by two themes: stacking blood-thinning supplements (omega-3, ginkgo, nattokinase, garlic), and stacking serotonin-raising ones (5-HTP, saffron, tryptophan), which matters most for anyone on medication. The flagged pairs:
Timing matters more than most people think, and the rules are not obvious.
Across 87 supplements with a meaningful timing rule, 76 (87%) absorb best with food, and the split between morning and evening is real, not random. Calming nutrients cluster at night; stimulating and fat-soluble ones cluster in the day.
A handful of nutrients are linked to the widest range of symptoms.
Across 40 common symptoms we analysed, the same few nutrients keep appearing. These are the ones worth ruling out first when something feels off, and the ones a simple blood panel covers.
A few ingredients are interaction hubs: Omega-3 Fish Oil alone appears in 13 of the 161 mapped pairs.
Interactions are not spread evenly. A handful of staples sit at the centre of the map, so if your stack contains one of these, it is worth checking before adding anything new. The most connected ingredients in the dataset:
Only a minority of popular supplements have strong evidence, and we say so.
Of the 200 supplements in the database, 85 (43%) are graded strong or very strong, with the rest moderate or emerging. The honest read: a small core (creatine, omega-3, vitamin D, magnesium, protein) is well-proven, and most of the rest is reasonable but not settled. Grading this openly, rather than hyping everything, is the point of suppdoc.
What 47 suppdoc users are actually stacking for.
Aggregated and anonymised from 47 quiz results, with an average stack costing about $56 per month. Top goals and most-clicked supplements:
Methodology and citation
Figures are derived from suppdoc.io's own structured datasets: 200 evidence-graded ingredient profiles, 161 hand-curated interaction pairs, 87 timing guides, 40 symptom-to-nutrient maps, and 20 biomarker references. The study-volume figure (71,776) is the deduplicated count of randomized controlled trials, meta-analyses and systematic reviews returned by per-ingredient PubMed queries; each ingredient page links to its exact search so the number can be verified. Interaction categories follow a fixed taxonomy (synergy, timing, redundant, caution). User figures, where shown, are aggregated and anonymised. This report updates as the datasets grow. Last updated 2026-06-12.
Free to cite and reference with a link to suppdoc.io. For data requests or press, contact hello@suppdoc.io.
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