Clinical studies on Zinc

1. Koshy et al., 2012 — Zinc + phytase with botulinum toxin

Study: Effect of dietary zinc and phytase supplementation on botulinum toxin treatments
Journal: Journal of Drugs in Dermatology
PMID: 22453589

Result: 77 patients; zinc citrate 50 mg + phytase was associated with ~30% longer toxin effect duration in many subjects, with 92% reporting increased duration and 84% reporting stronger effect. This included cosmetic facial rhytids, blepharospasm, and hemifacial spasm.

Systematic reviews / evidence summaries

2. Mallat et al., 2023 — Systematic review

Study: Botulinum Toxins and Zinc: From Theory to Practice—A Systematic Review
Journal: Clinical Neuropharmacology
PMID: 37335837

Result: The review searched PubMed and Embase, found 260 articles, retained  randomized controlled trials and 1 case report 3, and reported that 3 of the retained studies found significant improvement in toxin effect and longevity with zinc supplementation. 

3. Trindade Junior et al., 2023 — RCT systematic review focused on face muscles

Study: Effects of zinc supplementation on duration and action of botulinum toxin applied to face muscles
Journal: Journal of Trace Elements and Minerals

Result: This review found 2 eligible RCTs involving 123 people. It noted that 50 mg zinc + phytase increased BT treatment duration by 29.6% in one study.