What is the recommended oral dose of myo‑inositol for adults?

Myo-Inositol Dosing for Adults

The recommended oral dose of myo-inositol for adults is 2,000 mg (2 grams) twice daily, totaling 4,000 mg per day, typically combined with 200 mcg folic acid twice daily. 1, 2

Standard Dosing Protocol

For polycystic ovary syndrome (PCOS) and metabolic indications, initiate 2 grams twice daily (total 4 grams/day) continuously. 3, 2, 4

• This dosing regimen (4 g/day total) has demonstrated efficacy in restoring ovulatory function in 88% of PCOS patients within 6 months 4
• The combination with folic acid (400 mcg total daily) is standard practice, though myo-inositol alone remains effective 3, 2
• Treatment duration typically ranges from 2-6 months before assessing clinical response 2, 4

Safety and Tolerability Profile

Myo-inositol demonstrates excellent safety even at higher doses, with only mild gastrointestinal effects reported at maximum studied doses. 5

• Doses up to 12 grams daily have been studied, producing only mild nausea, flatulence, and diarrhea 5
• The severity of side effects does not increase proportionally with dosage 5
• No moderate to severe adverse effects occur at the standard 4 gram daily dose 2
• The FDA-approved product labeling recommends one capsule daily or as directed by a healthcare professional, though clinical studies consistently use higher doses 1

Clinical Context and Monitoring

For fertility and ovulation induction, maintain the 4 gram daily dose continuously while monitoring ovulatory activity through ultrasound and hormonal profiles. 4

• Spontaneous menstrual cycle restoration occurs in 72-88% of patients within the observation period 4
• Pregnancy rates of 15-40% have been documented with this dosing regimen 2, 4
• When used in IVF protocols, initiate treatment 2 months before starting the protocol 2

For metabolic improvements in PCOS, the same 4 gram daily dose significantly reduces testosterone levels and improves insulin sensitivity markers. 3, 2

• Testosterone levels decrease from approximately 96.6 ng/mL to 43.3 ng/mL after 12 weeks 2
• Progesterone levels improve from 2.1 ng/mL to 12.3 ng/mL after 12 weeks 2
• Both myo-inositol and D-chiro-inositol improve PCOS parameters, though myo-inositol shows superior metabolic effects 3

Important Caveats

Do not confuse myo-inositol with D-chiro-inositol—they are different compounds with distinct dosing regimens. 3

• D-chiro-inositol is typically dosed at 1 gram daily, not 4 grams 3
• Combination products use ratios of 40:1 to 100:1 (myo-inositol:D-chiro-inositol) 6
• Myo-inositol alone remains the most studied and recommended form for PCOS 6, 3

The standard 4 gram daily dose should be divided into two 2-gram doses rather than taken as a single daily dose. 2, 4