40:1 Myo and D-Chiro Inositol vs D-Chiro-Inositol
How 40:1 myo and D-chiro inositol and D-chiro-inositol differ in potency, absorption, tolerance, and cost.
This page contains affiliate links. Titrate earns a small commission when you purchase through them, at no cost to you. This does not affect our recommendations.
Side by Side
| Myo-Inositol and D-Chiro-Inositol (40:1) | D-Chiro-Inositol | |
|---|---|---|
| Absorption | Moderate | Moderate |
| How it is absorbed | Combines both isomers in roughly the ratio found in plasma. Absorption is that of each component. | Made in tissues from myo-inositol by an insulin-dependent epimerase. Supplemental DCI is absorbed but needed only in milligrams. |
| Typical dose | 2 g myo plus 50 mg DCI, twice daily | 50-600 mg daily, alone or with myo-inositol |
| Common uses | PCOS | PCOS (mostly in combination) |
| Side effects | As for myo-inositol. | Higher doses were linked to poorer oocyte quality in one IVF study. |
| Cost | Moderate | High |
| Also called | 40:1 blend, Ovasitol | DCI |
When to Choose Myo-Inositol and D-Chiro-Inositol (40:1)
Choose 40:1 myo and D-chiro inositol when you want the ratio tested in PCOS combination trials. The 40:1 ratio performed best for ovulation among ratios compared in one trial; myo-inositol alone remains the better-studied option.
Myo-Inositol and D-Chiro-Inositol (40:1)
Convenient for PCOS, with one trial supporting the ratio. Myo-inositol alone remains the better-studied option.
What to look for: 2 g myo-inositol and 50 mg D-chiro-inositol per serving, ratio stated.
Find on iHerb Affiliate linkWhen to Choose D-Chiro-Inositol
Choose D-chiro-inositol when a clinician has a reason to add DCI to myo-inositol. The ovary keeps a high myo to DCI ratio; flooding it with DCI may work against ovulation.
D-Chiro-Inositol
Rarely needed on its own. More is not better for the ovary.
What to look for: Use only with a clinician's reason, and only in small doses alongside myo-inositol.
Find on iHerb Affiliate linkProducts on Titrate
8,650 of the 214,745 labels in the NIH Dietary Supplement Label Database list inositol as an active ingredient (3,697 on market). 389 are sold as inositol products by name.
Inositol does not have its own search category yet. Each product above links to its full label in the NIH database.
Related
References
Unfer V, Carlomagno G, Dante G, Facchinetti F. Effects of myo-inositol in women with PCOS: a systematic review of randomized controlled trials. Gynecol Endocrinol. 2012;28(7):509-515.
Unfer V, Facchinetti F, Orrù B, Giordani B, Nestler J. Myo-inositol effects in women with PCOS: a meta-analysis of randomized controlled trials. Endocr Connect. 2017;6(8):647-658.
Nordio M, Basciani S, Camajani E. The 40:1 myo-inositol/D-chiro-inositol plasma ratio is able to restore ovulation in PCOS patients: comparison with other ratios. Eur Rev Med Pharmacol Sci. 2019;23(12):5512-5521.
Isabella R, Raffone E. Does ovary need D-chiro-inositol? J Ovarian Res. 2012;5(1):14.
Benjamin J, Levine J, Fux M, et al. Double-blind, placebo-controlled, crossover trial of inositol treatment for panic disorder. Am J Psychiatry. 1995;152(7):1084-1086.
Levine J, Barak Y, Gonzalves M, et al. Double-blind, controlled trial of inositol treatment of depression. Am J Psychiatry. 1995;152(5):792-794.
Fux M, Levine J, Aviv A, Belmaker RH. Inositol treatment of obsessive-compulsive disorder. Am J Psychiatry. 1996;153(9):1219-1221.
Palatnik A, Frolov K, Fux M, Benjamin J. Double-blind, controlled, crossover trial of inositol versus fluvoxamine for the treatment of panic disorder. J Clin Psychopharmacol. 2001;21(3):335-339.
Mukai T, Kishi T, Matsuda Y, Iwata N. A meta-analysis of inositol for depression and anxiety disorders. Hum Psychopharmacol. 2014;29(1):55-63.