Safety and Effectiveness of Soy Phytoestrogens to Prevent Bone Loss
Safety, Efficacy, and Optimal Dosage of Soy Isoflavones to Prevent Osteoporosis
  • Phase

  • Study Type

  • Status

    Completed No Results Posted
  • Intervention/Treatment

    soy isoflavones ...
  • Study Participants

The purpose of this study is to determine whether soy isoflavone supplementation is safe and effective to prevent bone loss in postmenopausal women.
Over-the-counter soy isoflavone supplement usage is becoming common among postmenopausal women. However, there is no documented scientific evidence of its long-term safety and efficacy in preventing osteoporosis. Our primary goal is to determine the safety, efficacy, and optimal dosage of isoflavone supplementation to reduce bone loss in postmenopausal women. The multi-state, multi-institutional design ensures that the study results are representative of postmenopausal women in the U.S. population. Confirming the skeletal benefits of soy isoflavones could translate into reduced healthcare costs related to osteoporosis.
Study Started
Apr 30
Primary Completion
Jun 30
Study Completion
Jun 30
Last Update
Nov 27

Dietary Supplement Placebo

Three pills per day for two years

Dietary Supplement Soy isoflavones

Three pills that delivered 80 mg of aglycone isoflavones per day for two years

  • Other names: Soy germ isoflavones

Dietary Supplement Soy isoflavones

Three pills that delivered 120 mg aglycone isoflavones per day for two years

  • Other names: Soy germ isoflavones

1 Placebo Comparator


2 Active Comparator

3 Active Comparator


Inclusion Criteria:

Must be able to swallow the pills
No menses for 12 months
Blood follicle stimulating hormone great than 30 IU/mL
Lumbar spine bone mineral density t-score equal to or greater than -1.5

Exclusion Criteria:

Strict vegetarians
Current or recent smokers (within last five years)
Abnormal screening mammogram, Pap smear and blood chemistries
Clinical diagnosis of osteoporosis, spine and/or hip fracture, cancer, liver, kidney, gallbladder and heart disease
Clinical diagnosis of psychiatric disorder
Any allergic reactions to soy products
Current treatment with bisphosphonates, calcitonin, fluoride, corticosteroids, tamoxifen, raloxifene, HRT, premarin, farestron and letrozole
Current usage of black cohosh, blue cohosh, dong quai, Caltrate 600+Soy, Estroven, ginseng, Healthy Women, Natural Estrogen, Opti-Soy, PhytoFem, Probalance, Promensil, Remifemin, Rimostil and Trinovin
No Results Posted