Calcium D-Glucarate
Summary
Calcium D-glucarate is the calcium salt of D-glucaric acid, a compound found in oranges, apples and cruciferous vegetables. Its proposed action, blocking the enzyme beta-glucuronidase, comes from rat studies. No published randomized trial has tested it alone in people; the one controlled trial used 150 mg/day inside a six-ingredient formula (grade D).
Key facts
- The calcium salt of D-glucaric acid, a compound the body makes in small amounts and that occurs in fruits and vegetables[1][3]
- None published with randomized controls; Memorial Sloan Kettering notes that clinical trials have not tested its proposed estrogen effects in humans[1]
- 150 mg/day inside a six-ingredient formula led by 400 mg/day indole-3-carbinol, for 28 days[2]
- 250 mg to 1,500 mg of calcium D-glucarate per day, about 1.7 to 10 times the trial amount[7][8][9][11][2]
- Glucaric acid measured from about 1.1 mg per 100 g (lowest, broccoli and potatoes) to 4.5 mg per 100 g (oranges)[4]
- 1 graded human outcome on this page
- October 13, 2026
How it works
ProposedIn rats given an oral D-glucarate salt (potassium hydrogen D-glucarate), D-glucaro-1,4-lactone formed in the stomach; this lactone inhibits beta-glucuronidase, an enzyme partly made by gut bacteria that frees estrogens and other compounds from their glucuronide tags so they can be reabsorbed. Blocking it is proposed to increase their excretion. This has not been confirmed in controlled human studies.[4][5][1][3]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Urinary estrogen metabolites (2-OHE and the 2:16α-OHE ratio) with a multi-ingredient formula | Mixed | Grade D | RCT · n = 68 · 2010 Pre- and post-menopausal women not using hormonal contraceptives or hormone therapy Form: Six-ingredient capsule: indole-3-carbinol 400 mg/day, HMR lignan 20 mg/day, milk thistle, calcium D-glucarate 150 mg/day, schisandra and stinging nettle · Dose: 150 mg/day calcium D-glucarate (75 mg per capsule, 2 capsules) within the formula · Duration: 28 days Urinary 2-OHE roughly doubled from baseline in the formula group but not with placebo. The 2:16α-OHE ratio rose significantly only in pre-menopausal women; across all women it was a trend (P=0.074). Among pre-menopausal women, headache and stomach pain were reported more often with the formula. | 21234288 (opens PubMed)Source [2] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Calcium D-glucarate capsules or tablets | Varies[7][8][9] | No human absorption study published. In rats, an oral D-glucarate salt (potassium hydrogen D-glucarate) formed D-glucaro-1,4-lactone in the stomach, was absorbed and was excreted mainly in urine.[5] | Memorial Sloan Kettering summarizes a preliminary human study in which it was well tolerated with no toxicity reported; in the 2010 formula trial headache and stomach pain were more common than with placebo, but the formula had six ingredients.[1][2] | Estrogen metabolism, as a minor ingredient in one formula trial |
| Glucaric acid in foods | Varies[4] | No head-to-head human data[4] | Normal dietary amounts in fruits and vegetables[4] | Food composition only (oranges, apples, grapefruit, cruciferous vegetables) |
Studied doses
Doses studied in human trials ranged from 150 mg/day of calcium D-glucarate, and only as a minor ingredient in one 28-day, six-ingredient formula trial. No randomized trial has tested calcium D-glucarate on its own at the 250–1,500 mg/day amounts found on labels.[2][7][8][9][11]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
None found in our sources.
Who should be careful
- Pregnancy and breastfeeding
- No safety data. The only controlled trial enrolled non-pregnant women, and product labels advise pregnant or breastfeeding women to consult a healthcare professional first.[2][7][8][11]
- Hormone-sensitive cancers
- Memorial Sloan Kettering notes that some people with breast cancer use calcium glucarate, but that no clinical trials have tested whether it lowers estrogen in humans. Anyone in cancer care should raise it with their oncology team.[1]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
How to read the label
- Label dose vs studied doseLabels list 250 mg, 500 mg, 1,000 mg (500 mg twice daily) or 1,500 mg of calcium D-glucarate per day. The only controlled trial used 150 mg/day, mixed with five other ingredients.[7][9][8][11][2]
- Glucarate, not calcium, is the pointThe calcium is a carrier; the glucarate is thought to account for any activity. Calcium per serving is small but counts toward total calcium intake.[1][8]
- Detox and hormone wordingClaims such as 'supports hormonal balance' or 'detoxification' rest on rat studies of beta-glucuronidase, not on human outcome trials.[1][4][9]
Cost per studied dose, without the sales pitch
Compare any product you already have by the amount it delivers, not by capsule count or front-of-pack weight.
Cost per studied dose
Enter the price, servings and the amount per serving from your label.
Where to buy Calcium D-Glucarate
Products from brands we partner with that contain Calcium D-Glucarate. Listing a product is not a claim that it works; check the amount per serving against the doses studied above, and the label for other ingredients.
- SupersmartPaid linkCalcium D-Glucarate3 capsules: 1,500 mg calcium D-glucarate (186 mg calcium); 30 servings. That is 10 times the 150 mg/day in the only controlled trial, which tested it inside a six-ingredient formula.Shop at Supersmart (opens in new tab)Price and label checked 2026-10-13 on the brand’s site.
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Frequently asked questions
Does calcium D-glucarate lower estrogen?
Not shown in people. Memorial Sloan Kettering notes that no clinical trials have tested this; the idea comes from rat studies of the enzyme beta-glucuronidase.[1][4]
Is there any human trial?
One 28-day randomized trial in 68 analysed women used 150 mg/day inside a six-ingredient formula. Urinary 2-OHE rose, but most of the formula was indole-3-carbinol, so the result cannot be credited to calcium D-glucarate.[2]
How is it supposed to work?
In rats it turns into D-glucaro-1,4-lactone, which blocks beta-glucuronidase. That enzyme can free estrogens and other compounds from their glucuronide tags so they are reabsorbed rather than excreted.[4][5]
Is calcium D-glucarate the same as indole-3-carbinol or DIM?
No. Calcium D-glucarate is the calcium salt of glucaric acid. The one formula trial that included it relied mainly on 400 mg/day of indole-3-carbinol; our DIM page covers that line of evidence.[3][2]
Can you get glucaric acid from food?
Yes, in small amounts: about 4.5 mg per 100 g in oranges and roughly 1–2 mg per 100 g in broccoli and potatoes.[4]
Sources
- [1]Calcium Glucarate (About Herbs, Botanicals & Other Products). Memorial Sloan Kettering Cancer Center, 2022. database
- [2]Effects of a breast-health herbal formula supplement on estrogen metabolism in pre- and post-menopausal women not taking hormonal contraceptives or supplements: a randomized controlled trial.. Breast Cancer (Auckl), 2010. RCT
- [3]Calcium-D-glucarate.. Altern Med Rev, 2002. review
- [4]Effect of calcium glucarate on beta-glucuronidase activity and glucarate content of certain vegetables and fruits.. Biochem Med Metab Biol, 1990. animal-study
- [5]Metabolism, uptake, and excretion of a D-glucaric acid salt and its potential use in cancer prevention.. Cancer Detect Prev, 1997. animal-study
- [6]Calcium glucarate as a chemopreventive agent in breast cancer.. Isr J Med Sci, 1995. review
- [7]Seeking Health Calcium D-Glucarate (label 210800). NIH Dietary Supplement Label Database, 2020. label
- [8]XYMOGEN Calcium D-Glucarate (label 27826). NIH Dietary Supplement Label Database, 2013. label
- [9]Natrol Calcium D-Glucarate (label 55575). NIH Dietary Supplement Label Database, 2016. label
- [10]Calcium: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements, 2026. fact-sheet
- [11]SuperSmart Calcium D-Glucarate (label 332639). NIH Dietary Supplement Label Database, 2025. label
What changed
- Adversarial review pass: every row re-read against its abstract or full text. Fixed: rat metabolism study used potassium hydrogen D-glucarate (not the calcium salt); label range restated as 1.7–10 times the trial amount; trial credit now names both indole-3-carbinol and HMR lignan; calcium-per-serving figure tied to a cited label; unsourced DIM wording removed. Retraction and expression-of-concern checks on all 5 PMIDs: none flagged (the 2010 trial has a 2012 erratum, noted). Page set indexable.
- First draft. Every PMID checked against NCBI E-utilities esummary (title and year from the record); the 2010 trial's ingredient amounts, analysed numbers and adverse events taken from its PMC full text (PMC3018890). Label amounts from the NIH Dietary Supplement Label Database. No NIH ODS or NCCIH fact sheet covers calcium D-glucarate.