Our library offers providers with in-depth reviews of ingredients commonly found in supplements. Each review contains information about the ingredient’s clinical applications, formulations, dosing and administration, adverse effects, and pharmacokinetics.
Inositol
Inositol is a constituent of phospholipids in cellular membranes, a precursor of secondary messengers in metabolic pathways, a component of reproductive fluids, and essential for tissue growth. (32)(39) Previously considered an essential B vitamin (vitamin B8), it is now known that the human body can synthesize four grams of inositol per day, whereas approximately one gram per day can be obtained from the diet. (14) For this reason, inositol is now mainly referred to as an essential pseudovitamin. (24)
Not be confused with: D-pinitol (structurally related)
Main uses
- Endocrine disorders
- Hormonal and reproductive disorders
- Metabolic disorders
- Neurological disorders
Formulations
| Formulation | Comparison | |
|---|---|---|
|
Myo-inositol |
Hormonal and reproductive: mature oocytes, embryo quality, & sex hormone-binding globulin (SHGB); Hormonal and reproductive: LH/FSH ratio, total testosterone, HOMA index, and immature oocytes by MI compared with D-chiro-inositol supplements in polycystic ovarian syndrome patients (34)(40) Endocrine: More involved in regulating intestinal glucose absorption in rats (9) More involved in glucose uptake from plasma via glucose receptor activation (16) |
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|
D-chiro-inositol |
||
Dosing & administration
| Female infertility under in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) | ||
|---|---|---|
|
General outcomes from A-level evidence |
No data currently available. |
|
|
Dosing & administration
|
2000 mg (MI) + 200 μg folic acid twice per day for 3 months in non-PCOS women undergoing IVF or ICSI |
|
|
Outcomes |
r-FSH to form mature follicles, number of retrieved oocytes, metaphase II eggs, inseminated eggs, 2PN oocytes & embryos LH (29) |
|
|
Class of evidence
|
B |
|
|
Dosing & administration
|
4000 mg (MI) + 400 μg folic acid for 3 months in IVF poor-responders |
|
|
Outcomes |
r-FSH, low quality oocytes (M1, Germinal Vesicle, only zona and degenerated oocytes) mature oocytes retrieved, ovarian sensitivity index. Trended towards increased fertilization, implantation, grade 1 embryo, & pregnancy rates (6) |
|
|
Class of evidence
|
B |
|
| Gestational diabetes (GDB) | ||
|---|---|---|
|
General outcomes from A-level evidence |
No data currently available. |
|
|
Dosing & administration
|
2000 mg (MI) twice per day
|
|
|
Outcomes |
rate of GDB & preterm delivery (42) |
|
|
Class of evidence
|
A |
|
|
Dosing & administration
|
4000 mg (MI) + 400 μg folic acid per day for 8 weeks |
|
|
Outcomes |
fasting glucose & insulin, HOMA-IR adiponectin (1) |
|
|
Class of evidence
|
B |
|
|
Dosing & administration
|
4000 mg (MI) + 400 μg folic acid per day over pregnancy duration |
|
|
Outcomes |
GDB incidence, insulin therapy requirements, baby size with decreased rate of neonatal hypoglycemia gestational age of delivery (30) |
|
|
Class of evidence
|
B |
|
|
Dosing & administration
|
2000 mg (MI) + 200 μg folic acid per day from 1st trimester to delivery |
|
|
Outcomes |
rate of GDB, HOMA-IR (13) |
|
|
Class of evidence
|
B |
|
| Male infertility | ||
|---|---|---|
|
General outcomes from A-level evidence |
No data currently available. |
|
|
Dosing & administration
|
2000 mg (MI) twice per day for 1 year |
|
|
Outcomes |
number of px with metabolic syndrome via ↓ serum glucose, insulin, TGs, total cholesterol, BP, HOMA-IR HDL-C (35) |
|
|
Class of evidence
|
B |
|
|
Dosing & administration
|
2000 mg (MI) twice per day for 6 months |
|
|
Outcomes |
DBP (11%), TGs (20%), HOMA-IR (75%) HDL-C (22%) (20) |
|
|
Class of evidence
|
B |
|
| Metabolic syndrome in post-menopausal women | ||
|---|---|---|
|
General outcomes from A-level evidence |
No data currently available. |
|
|
Dosing & administration
|
2000 mg (MI) twice per day for 1 year |
|
|
Outcomes |
number of px with metabolic syndrome via ↓ serum glucose, insulin, TGs, total cholesterol, BP, HOMA-IR HDL-C (35) |
|
|
Class of evidence
|
B |
|
|
Dosing & administration
|
2000 mg (MI) twice per day for 6 months |
|
|
Outcomes |
DBP (11%), TGs (20%), HOMA-IR (75%) HDL-C (22%) (20) |
|
|
Class of evidence
|
B |
|
| Panic disorder | ||
|---|---|---|
|
General outcomes from A-level evidence |
No data currently available. |
|
|
Dosing & administration
|
1200 mg (inositol) per day for 1 month |
|
|
Outcomes |
panic attack frequency & agoraphobia severity (3) |
|
|
Class of evidence
|
C |
|
| Polycystic ovarian syndrome | ||
|---|---|---|
|
General outcomes from A-level evidence |
No data currently available. |
|
|
Dosing & administration
|
1.0-4.0 g (MI) + 400 μg folic acid for 12-24 weeks; divided doses, twice per day
|
|
|
Outcomes |
fasting serum insulin, HOMA index, leptin, LH, prolactin, testosterone, androstenedione, LH/FSH, TGs, SBP, DBP, 1st ovulation time, immature oocytes, & associated erythrocyte oxidative stress |
|
|
Class of evidence
|
A |
|
|
Dosing & administration
|
100 mg (inositol) twice per day for 14 weeks |
|
|
Outcomes |
ovulation frequency (23%), estradiol, weight loss, HDL 1st ovulation time (23.6 days), ovulation failure frequency, leptin (18) |
|
|
Class of evidence
|
B |
|
|
Dosing & administration
|
1200 mg (DCI) daily for 6-8 weeks |
|
|
Outcomes |
||
|
Class of evidence
|
C |
|
|
Dosing & administration
|
550 mg (MI) + 13.8 mg (DCI) twice per day for 6 months |
|
|
Outcomes |
LH, free testosterone, fasting insulin, HOMA index 17-beta-estradiol (2) |
|
|
Class of evidence
|
C |
|
| Respiratory distress syndrome in preterm infants | ||
|---|---|---|
|
General outcomes from A-level evidence |
No data currently available. |
|
|
Dosing & administration
|
120-160 mg/kg (MI, intravenously) for the first 10 days of life |
|
|
Outcomes |
ventilation support, deaths, bronchopulmonary dysplasia ductus arteriosus closure ( 2) |
|
|
Class of evidence
|
B |
|
|
Dosing & administration
|
80 mg/kg (MI intravenously) for first 5 days of life |
|
|
Outcomes |
requirements for inspiratory O2 & airway pressure, bronchopulmonary dysplasia, premature retinopathy (21) |
|
|
Class of evidence
|
B |
|
Adverse effects
At doses greater than 12 g per day, gastrointestinal effects, such as nausea, flatulence, and diarrhea, may occur. However, the incidence of these events is considered mild and does not increase in severity as the dose increases. (8) Increasing doses (300 to 2400mg) of DCI has been shown to negatively impact oocyte quality in patients with PCOS. (25)
Pharmacokinetics
Absorption
Distribution
- SMIT1/SMIT2 and the H+ myo-inositol transporter are responsible for inositol uptake throughout the body and brain. (14)
- Myoinositol can pass the blood-brain barrier for distribution to the brain and cerebrospinal fluid in rats. (36)(37)
- Myoinositol is also distributed to seminal fluids, prostate, epididymis, and seminal vesicles, and is high in follicular fluid of healthy Px, but low in PCOS Px. (4)
- D-chiro-inositol is highly distributed to fat, muscle, and the liver, but is low in the brain and heart in humans. (31)
- D-chiro-inositol is high in follicular fluid of PCOS Px, but low in healthy Px. (4)