Supplement Label Index

Boron Glycinate vs. Calcium Fructoborate

Among 2,843 on-market boron products with an identifiable primary form, 21.1% use Boron Glycinate (601 products) and 4.6% use Calcium Fructoborate (131).

Boron GlycinateCalcium Fructoborate
Quality tierUnratedUnrated
Boron by weight—2.5%
Share of market21.1%4.6%
On-market products601131
Median declared dose1.5 elemental mg
middle half: 1–3
5.4 elemental mg
middle half: 3–6
Most common brandsPure Encapsulations, Life Extension, ProCaps LaboratoriesVibrant Health, Purity Products, Schiff

Doses are declared per serving in elemental mg. “By weight” is the share of the ingredient that is the nutrient itself (e.g. elemental magnesium in a magnesium salt).

Why Boron Glycinate is unrated

No head-to-head human bioavailability or efficacy comparison of this form was located in PubMed searches.

Why Calcium Fructoborate is unrated

The only form here with form-specific clinical trials we located (110mg twice daily for 14 days for knee discomfort, n=60, industry-affiliated authors; a 2021 erratum exists); no comparison of boron absorption against other boron forms was located, so no tier is assigned.

Source: Pietrzkowski Z et al. 2014, Clin Interv Aging 9:895-9, PMID 24940052

Tiers summarize published comparative bioavailability or outcome evidence for each form (see methodology). This page describes the market; it is not a recommendation to take either form. Talk to a clinician about what's right for you.

Other boron comparisons