From the databaseWhat the row says.
Every entry follows the same shape: what is happening, the mechanism, and the recommendation.
Scope
Supplement × Supplement
Last verified
June 4, 2026
SynergyInsufficient evidence
What is happening. Adequate vitamin D supports muscle function when deficient, but direct ecdysterone synergy is unproven.
Mechanism. Complementary musculoskeletal support mechanisms.
Recommendation. Correct deficiency rather than using high-dose vitamin D indiscriminately.
Stack Score
How it moves the number.
Effect on the composite score
If both Ecdysterone and Vitamin D3 are in the same stack, this pair applies +2 to your Stack Score (per scored synergy row).
The full algorithm, the clamping rules, and four worked stacks are at /methodology/stack-score.
SourcesSources, by evidence tier.
Every claim on this page is cited. PMIDs link straight to PubMed.
Reference material
1- 1Parr MK et al. Ecdysteroids review. Biol Sport. 2015.Needs sourceNo link