Best Myo-Inositol Supplements 2026: Cost per Effective Dose
Our pick is Ovasitol: $0.96 a day for 4 g of myo-inositol. It is $86.68 for a 180-serving tub, on NSF/ANSI 173, and it costs the least of the 3 products on a public testing list. Across all 9 we score, 4 g a day costs $0.26 to $2.22 at each brand’s list price; the buy button opens the Amazon listing.
By Erin Rose Updated October 20, 2026 How we score
Why it is our pick: the best myo-inositol.
What each myo-inositol costs for 4 g a day, cheapest first
| Product and pack | 4 g a day | A year |
|---|---|---|
| Nutricost Myo-Inositol Powder 1 lb tub, list $29.97; 4 g is 4 scoops; plain myo-inositolCheck price | $0.26 | $96 |
| Micro Ingredients Myo & D-Chiro Inositol Powder 1 lb tub, list $49.95; 4 g is 2 scoops; 40:1 with D-chiroCheck price | $0.45 | $165 |
| Zazzee Pregnositol Powder 183-serving tub, list $59.97; 4 g is 2 scoops; 40:1 with D-chiro | $0.66 | $239 |
| Pure Encapsulations Inositol Powder 8.8 oz tub, list $54.00; 4 g is 1 scoop; plain myo-inositolCheck price | $0.90 | $329 |
| Ovasitol Inositol Powder our pick 180-serving tub, list $86.68; 4 g is 2 scoops; 40:1 with D-chiroOn NSF/ANSI 173Check price | $0.96 | $352 |
| Jarrow Formulas Inositol 750 mg 100-capsule bottle, list $18.99; 4 g is 5 to 6 capsules; plain myo-inositolCheck price | $1.01 | $370 |
| Fairhaven Health Myo & D-Chiro Inositol 120-count bottle, list $24.99; 4 g is 8 capsules; 40:1 with D-chiroCheck price | $1.67 | $608 |
| Wholesome Story Myo & D-Chiro Inositol 120-capsule bottle, list $27.95; 4 g is 8 capsules; 40:1 with D-chiroOn NSF/ANSI 173Check price | $1.86 | $680 |
| Momentous Inositol 120-capsule bottle (60 servings), list $29.99; 4 g is 8 to 9 capsules; plain myo-inositolOn NSF Certified for Sport and NSF/ANSI 173Check price | $2.22 | $811 |
To choose by need, see the best myo-inositol. Which ones are on a list: third-party tested myo-inositol.
What “4 g a day” means here
Many trials used 4 g of myo-inositol a day, often 2 g twice a day. No guideline names a dose. To compare prices fairly, we price every product at 4 g of myo-inositol a day. It is a way to compare cost, not a dose for you to follow. Follow the serving on your label.
Why a label’s cost per serving looks cheaper
6 of the 8 labels we could read say to take less than 4 g a day. So their cost per serving looks low. Compare the cost of 4 g instead.
| Product | Label, a day | Cost on the label | Cost of 4 g |
|---|---|---|---|
| Nutricost | 1 g | $0.07 | $0.26 |
| Jarrow 750 mg | 0.75 g | $0.19 | $1.01 |
| Zazzee Pregnositol | 2 g | $0.33 | $0.66 |
| Momentous | 0.9 g | $0.50 | $2.22 |
| Fairhaven Health | 2 g | $0.83 | $1.67 |
| Wholesome Story | 2 g | $0.93 | $1.86 |
The cheapest is not our pick
Nutricost is the lowest at $0.26 a day for 4 g. It is plain myo-inositol, and its label says 1 g a day, so 4 g is 4 scoops. Micro Ingredients is the cheapest 40:1 powder at $0.45. Both say “tested” on their stores but name no lab, and no public list names either one. Ovasitol is the cheapest product that a public testing list checks, at $0.96. Why we pick it.
Buy the biggest tub you will finish
A bigger size saves a little. At the brand’s own price, Wholesome Story costs $1.86 a day in the 120 capsules size and $1.55 in the 360 capsules size, about 17% less. Buy a size you will finish before its date.
| Product and size | 4 g a day | A year |
|---|---|---|
| Wholesome Story 120 capsules, list $27.95 (the size we link) | $1.86 | $680 |
| Wholesome Story 360 capsules, list $69.95 | $1.55 | $567 |
| Micro Ingredients 1 pound, list $49.95 (the size we link) | $0.45 | $165 |
| Micro Ingredients 2 pounds, list $88.95 | $0.40 | $147 |
| Fairhaven Health 120 ct, list $24.99 (the size we link) | $1.67 | $608 |
| Fairhaven Health 240 ct, list $44.99 | $1.50 | $547 |
Amazon sets its own prices, and we quote none here. If Amazon’s price is lower than the list price, your day costs less too. To compare, divide the Amazon price by the grams of myo-inositol in the tub, then multiply by 4.
You may not need it. The research on myo-inositol is small and mixed (what it found). Ask your doctor first if you are pregnant, breastfeeding or trying to get pregnant, if you take lithium or valproate, or if you take a prescription medicine such as metformin or another diabetes medicine.
Sources
- Prices: each brand’s own one-time list price (not subscribe or sale), for every size it sells, checked October 13, 2026. We quote no Amazon prices; Amazon is only where the buy links go.
- Amounts: each product’s label (NIH Dietary Supplement Label Database, or the brand’s page for Micro Ingredients and Momentous).
- Testing lists: NSF/ANSI 173, NSF Certified for Sport, and Informed Sport and Informed Choice, searched October 13, 2026; USP Verified. Details: third-party tested myo-inositol.
- 5 more we could not score: we found no list price we can cite for most of them. Details. Scores updated October 13, 2026.