What the Research Shows: Clinical Evidence Summary
Women’s Twice Daily provides high-potency vitamins/minerals (including 2 mg copper bisglycinate chelate), synergistic bone cofactors, and hormone botanicals at doses contributing to comprehensive hormone, bone, and immune support. Note: Individual ingredient RCTs typically evaluate single agents at higher doses than in multi-formula packets.
*These studies explore outcomes related to individual ingredients used in Women’s Twice Daily. Research on individual ingredients does not necessarily reflect the effect of the full formula. When study doses differ from Women’s Twice Daily, we note it. Not intended to diagnose, treat, cure, or prevent any disease.
Vitamin K2 MK-7 (MenaQ7®, 90-180 µg/day)
Studied for: decreased age-related decline in bone mineral density (BMD) and strength at lumbar spine/femoral neck in postmenopausal women (3-year RCT).cris.maastrichtuniversity+2
Dose note: RCT used 180 µg/day. Formula: 90-180 µg/day. (PubMed)
Further reading:
Knapen et al., 2013 (RCT): PubMed
MenaQ7 clinical summary: MenaQ7 PDF
Calcium (800 mg/day, bisglycinate) + Vitamin D (2,000 IU/day) + Magnesium (400 mg/day)
Studied for: reduced total fracture risk (14-15%) and hip fractures (~30%) in middle-aged/older adults (meta-analyses of RCTs).bonehealthandosteoporosis+2
Dose note: Trials typically 1,000-1,200 mg calcium + 800 IU D; formula stacks comparable foundational levels. (JAMA)
Further reading:
Kahwati et al., 2019 (USPSTF review): JAMA
Jackson et al., 2015 (Women's Health Initiative): PMC
Copper Bisglycinate Chelate (2 mg/day)
Studied for: serum copper often low in osteopenic/osteoporotic postmenopausal women; combined with calcium/zinc/manganese, 2.5 mg copper helped maintain lumbar spine BMD vs. placebo (2-year RCT).pmc.ncbi.nlm.nih+2
Dose note: RCT used 2.5 mg/day in multi-mineral mix. Formula: 2 mg/day (well below 10 mg UL). (PMC)
Further reading:
Mahdavi-Roshan et al., 2015 (observational): PMC
Nielsen et al., 1990 (RCT): PubMed
Bioavailability study: PMC
Zinc Bisglycinate (15 mg/day) + Magnesium Bisglycinate (200 mg/day)
Studied for: dietary/serum zinc and magnesium often below RDA in postmenopausal women with low bone density; deficiencies linked to impaired bone matrix synthesis.frontiersin+2
Dose note: Observational data; formula provides bioavailable chelates at corrective levels. (PMC)
Further reading:
Mahdavi-Roshan et al., 2015: PMC
Boron (Bororganic Glycine, 2 mg/day)
Studied for: reduced urinary calcium loss, increased serum estradiol and vitamin D in postmenopausal women (metabolic studies).cambridge+2
Dose note: Studies used ~3 mg/day. Formula: 2 mg/day. (PMC)
Further reading:
Nielsen, 2015 (review): PMC
Vitamins C (500 mg/day), D (2,000 IU/day), Zinc (15 mg/day), Selenium (200 µg/day)
Studied for: improved immune parameters (lymphocytes, infection duration) in older adults; key roles in innate/adaptive immunity (RCTs/reviews).pmc.ncbi.nlm.nih+2
Dose note: Multi-micronutrient RCT used similar foundational levels. (PMC)
Further reading:
White et al., 2020 (RCT): PMC
B Vitamins (High-potency methylated B-complex)
Studied for: modest improvements in stress, mood, and fatigue in healthy/at-risk adults (meta-analysis of RCTs).pmc.ncbi.nlm.nih+2
Dose note: Trials used high-dose B-complex. Formula provides methylated forms. (PMC)
Further reading:
Young et al., 2019 (meta-analysis): PMC
References and full PDFs available upon request. Structure/function claims supported by cited peer-reviewed RCTs and meta-analyses.