Just because a supplement is not tested by one of these three companies does not mean it’s a bad product. We recommend doing some research on the reputability of the manufacturer, and calling the manufacturer and its testing lab to determine their protocols and decide if you feel comfortable consuming the supplement. The most common undesirable effect is gastric irritation. This is usually worst with the first morning dose and disappears after the first days of treatment. Delaying the first dose to mid-morning or taking the dose with a little protein may usually relieve the symptoms.

Marshall S. Zinc gluconate and the common cold. Review of randomized controlled trials. Can Fam Physician. 1998;44:1037-1042.Pharmacodynamic studies were conducted in Wilson's disease patients on the combination of Wilzin (50 mg three times daily) with ascorbic acid (1 g once daily), penicillamine (250 mg four times daily), and trientine (250 mg four times daily). They showed no significant overall effect on copper balance although mild interaction of zinc with chelators (penicillamine and trientine) could be detected with decreased faecal but increased urinary copper excretion as compared with zinc alone. This is probably due to some extent of complexion of zinc by the chelator, thus reducing the effect of both active substances. Diarrhea Symptoms - Lazzerini M, Wanzira H Oral zinc for treating diarrhoea in children. Cochrane Database Syst Rev. (2016-Dec-20)

Wang L, Song Y Efficacy of zinc given as an adjunct to the treatment of severe pneumonia: A meta-analysis of randomized, double-blind and placebo-controlled trials. Clin Respir J. (2018-Mar)

Mucositis Symptoms - Ertekin MV, Koç M, Karslioglu I, Sezen O Zinc sulfate in the prevention of radiation-induced oropharyngeal mucositis: a prospective, placebo-controlled, randomized study Int J Radiat Oncol Biol Phys. (2004 Jan 1) Insulin - Hashemipour M, Kelishadi R, Shapouri J, Sarrafzadegan N, Amini M, Tavakoli N, Movahedian-Attar A, Mirmoghtadaee P, Poursafa P Effect of zinc supplementation on insulin resistance and components of the metabolic syndrome in prepubertal obese children Hormones (Athens). (2009 Oct-Dec) Camacho EM, Huhtaniemi IT, O'Neill TW, Finn JD, Pye SR, Lee DM, Tajar A, Bartfai G, Boonen S, Casanueva FF, Forti G, Giwercman A, Han TS, Kula K, Keevil B, Lean ME, Pendleton N, Punab M, Vanderschueren D, Wu FC, EMAS Group Age-associated changes in hypothalamic-pituitary-testicular function in middle-aged and older men are modified by weight change and lifestyle factors: longitudinal results from the European Male Ageing Study Eur J Endocrinol. (2013 Feb 20) Dording CM, Schettler PJ, Dalton ED, Parkin SR, Walker RS, Fehling KB, Fava M, Mischoulon D A double-blind placebo-controlled trial of maca root as treatment for antidepressant-induced sexual dysfunction in women Evid Based Complement Alternat Med. (2015) Wehr E, Pilz S, Boehm BO, März W, Obermayer-Pietsch B Association of vitamin D status with serum androgen levels in men Clin Endocrinol (Oxf). (2010 Aug)

Upper Respiratory Tract Infection Symptoms - Farr BM, Conner EM, Betts RF, Oleske J, Minnefor A, Gwaltney JM Jr Two randomized controlled trials of zinc gluconate lozenge therapy of experimentally induced rhinovirus colds Antimicrob Agents Chemother. (1987 Aug) Zinc citrate is approximately 34% zinc by weight. For a dose of 50mg elemental zinc, take 146 mg zinc citrate.It is important to note that phytate compounds found in rich plant sources of zinc have been shown to have antioxidant properties that offer protection against cancer, cardiovascular disease and diabetes. Limiting the intake of animal sources of zinc, on the other hand, is likely a good move towards a more healthful lifestyle. This is because animal-based foods high in saturated fat and cholesterol have been associated with increased risk of various chronic diseases. To ensure adequate intake of zinc (8 milligrams for women and 11 milligrams for men), be sure to consume foods rich in zinc daily. If you are already consuming a diet high in zinc and meeting your dietary requirements, it is not advisable to take additional zinc in the form of supplements. With high intake of zinc through food sources, there is no need to be concerned about overconsumption, as the body will compensate accordingly. Overconsumption of zinc usually occurs when supplements are consumed rather than using foods. Uwitonze AM, Razzaque MS Role of Magnesium in Vitamin D Activation and Function J Am Osteopath Assoc. (2018 Mar 1) Upper Respiratory Tract Infection Symptoms - Weismann K, Jakobsen JP, Weismann JE, Hammer UM, Nyholm SM, Hansen B, Lomholt KE, Schmidt K Zinc gluconate lozenges for common cold. A double-blind clinical trial Dan Med Bull. (1990 Jun) Total cholesterol - Asbaghi O, Sadeghian M, Fouladvand F, Panahande B, Nasiri M, Khodadost M, Shokri A, Pirouzi A, Sadeghi O Effects of zinc supplementation on lipid profile in patients with type 2 diabetes mellitus: A systematic review and meta-analysis of randomized controlled trials. Nutr Metab Cardiovasc Dis. (2020-Jul-24)