The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
Adults (over 18 years old)
Soy protein dosing is controversial and consistent clinical effects have been lacking. In the United States, 25 milligrams daily of soy has been approved for decreasing cholesterol. Incidence of breast and prostate cancer is low in Asia, therefore dietary soy intake has been investigated.
As an antioxidant, 25 grams of soy protein in a single shake has been taken by mouth for up to eight weeks and 50 grams of soy (kinako) has been used daily for 90 days.
For cancer (prevention and treatment), 20-58 grams of soy protein for six weeks to six months has been taken by mouth; also 8 ounces of soymilk has also been taken three times daily for 12 months.
For heart health, 25-50 grams of soy protein (e.g. Abalon®), and soy-containing foods (such as tofu and yogurt), and soy foods with 40-60mg isoflavones have been taken by mouth daily for 4-52 weeks.
For gallstone prevention, soy protein has been taken by mouth for two weeks.
For cognitive function, 25.6 grams or an unknown dose of soy protein, soy supplement, or soymilk (containing 60-160mg isoflavones) have been taken by mouth daily for 3-12 months.
For Crohn's disease, soya-derived protein has been added to standard enteral treatment for four weeks.
For cyclical breast pain, 17 grams of soy protein as a beverage has been taken by mouth twice daily for three months.
For diabetes, 11.3-111 grams of soy protein or 0.5-0.8 grams per kilogram soy protein (e.g. Abalon®) has been taken by mouth daily for periods of four weeks to four years. Also, fermented soybean touchi tea has been taken by mouth for three months, a single dose of 7-10 grams of soy fiber or a meal with 10 grams soy polysaccharide has been used as a single dose; 52 grams of soy hull fiber has been taken by mouth daily for four weeks; and a soy protein diet has been followed for eight weeks.
For enhancement of exercise performance, 0.4-1.5 grams per kilogram of soy protein divided has been used once to three times daily for 6-8 weeks; and a fat-free soy protein drink has been taken by mouth twice daily post-exercise, five days weekly for 12 weeks.
For fibromyalgia, a shake with 20 grams of soy protein and 160 milligrams of soy isoflavone has been taken by mouth daily for six weeks.
For high blood pressure, 15-66 grams of soy protein has been taken by mouth daily for 4-52 weeks; also 500 milliliters of soymilk has been taken twice daily for three months.
For inflammation due to hemodialysis, soy protein has been taken by mouth for eight weeks.
For iron deficiency anemia, two capsules of shoyu polysaccharides has been taken by mouth twice daily for four weeks.
For kidney disease, the following diets have been followed for seven weeks to six months: a soy-based vegetable low-protein diet; a 35% soy protein and 30% vegetable protein diet; a diet with soy protein as half of the daily protein intake.
For lowering cholesterol, 11.3-140 grams of soy protein has been taken by mouth daily for 3-52 weeks.
For the menopausal symptom hot flush, 33.3-134.4 milligrams of soy supplement, extract, or protein has been taken by mouth daily for 12-96 weeks. Dietary soy powder (Previna®) containing 12 milligrams of soy protein and 45 milligrams of isoflavones has been taken by mouth twice daily for 16 weeks. Also, 40-134 milligrams of soy isoflavones has been taken by mouth daily for 6-26 weeks.
For non-hot flush menopausal symptoms, soy protein, soy supplement, or soymilk (containing 60-160 milligrams of isoflavones has been taken daily for 3-12 months; also a dose of 25 grams of soy protein has been used for up to 12 months.
For metabolic syndrome, soy protein has been taken by mouth for eight weeks in place of animal protein.
For motility disorders, 15 grams of soy polysaccharide fiber have been taken by mouth daily for up to 18 days.
For osteoarthritis, 40 grams of soy protein has been taken by mouth daily for three months.
For osteoporosis, 500 milliliters of soymilk has been taken daily for 1-2 years; also 80.4 milligrams to 40 grams of soy protein has been taken daily for three months to one year.
For premenstrual syndrome (PMS), 30.5 grams of soy protein isolate has been taken daily for seven months.
For rheumatoid arthritis, soy peptide has been taken by mouth for four weeks.
For skin damage, a skin cream containing soy ingredients has been applied to the skin for 12 weeks.
For spinal cord injury, 48 grams of a vanilla-flavored soy drink has been taken by mouth.
For weight loss, 15 grams of soy protein per 1,000 kilocalories has been taken by mouth daily for up to 12 weeks (as five meal replacements, three soy shakes, or soy foods); four pieces of beta-conglycin candy (0.625 grams of beta-conglycin per candy) has been taken by mouth twice daily for reduction of visceral fat; a soya-based liquid formula for two meals daily with was taken by mouth for four weeks; a soy-based low-calorie diet has been followed for eight weeks; five foods prepared with isolated soy protein have been consumed to maintain a protein intake between 86-96 grams daily for 30 days; 25 milligrams of soy isolate (containing 59% protein) or soy concentrate (containing 59.5% protein) has been taken by mouth twice daily for 12 weeks.
Children (under 18 years old)
Soy is generally considered safe for eating by infants and children according to both traditional knowledge and research. Due to potential safety concerns, a qualified healthcare provider should be consulted regarding the choice of infant formula.
For acute diarrhea in infants and young children, soy formula has been studied for up to 14 days; utilized brands included Nursoy® and Isomil®.
To prevent food allergies in infants, soy formula has been studied.
For infantile colic, various soymilk formulas (e.g. ProSobee®, Soy Enfamil®, Isomil®) have been taken for periods of 48 hours to 28 days.
For iron deficiency anemia, a 16 ounce of soy-based formula has been used daily for 12 weeks.
For lowering cholesterol levels, children took soy protein by mouth for four weeks.
For weight gain in infants, soy formula has been taken by mouth over a 6-12 month period.
This evidence-based monograph was prepared by The Natural Standard Research Collaboration