Are pistachios high in oxalate?
No. Low, 9 mg per 1 oz (about 49 nuts)
Range 8.9 to 16 mg across 2 studies, 28 g serving
Pistachios are low in oxalate: about 9 mg per 1 oz (about 49 nuts), which is 18% of the 50 mg a day many stone clinics aim for, or 9% of the 100 mg others allow.
50 or 100 mg a day: which target is yours
Why sources disagree on pistachios
The 2 studies here run from 8.9 to 16 mg per 1 oz (about 49 nuts), measured between 2021 and 2023. They tested 3 preparations, and growing conditions, variety and lab method all move the number.
Where this number comes from
Each row is one published measurement, converted to a 28 g serving (1 oz (about 49 nuts)). The grade and the range use the rows prepared the way the serving is eaten, and take the middle. How the grades work.
| Per serving | Per 100 g | Preparation | Source |
|---|---|---|---|
| 8.9 mg | 31.7 mg | dry roasted, unsalted | Harvard T.H, 2023 |
| 9 mg | 32.14 mg | Dry roasted | Harvard T.H, 2023 |
| 16 mg | 56.5 mg | as sold (not specified) | Siener R, 2021 |
| 22 mg soluble only* | 77 mg | roasted | Ritter MMC, Savage GP, 2007 |
* The study measured soluble oxalate only, which understates the total, so it's shown but doesn't set the grade.
By Oliver Silen · Data checked November 2, 2026 · Not medical advice