Benefits
Supports joint comfort and mobility
In people with knee discomfort, calcium fructoborate (the molecule in Promentum) has been reported to help improve joint comfort, stiffness, and physical-function scores, with benefits often noted within the first week or two and building over continued use. It is studied as a daily support option for everyday joint wear.
Helps maintain a healthy inflammatory balance
Small human studies of calcium fructoborate found reductions in blood inflammation markers such as C-reactive protein and cytokines (IL-6, MCP-1), in osteoarthritis patients and in healthy adults. These are laboratory biomarker changes, not a measured reduction in disease, and the trials were short and manufacturer-run.
Supplies boron involved in mineral metabolism
Boron takes part in how the body handles calcium, magnesium, and vitamin D, minerals involved in bone remodeling. No trial of Promentum or calcium fructoborate has measured bone density, bone turnover markers, or fracture risk, so any effect on bone strength in people is unproven.
Supplies bioavailable dietary boron
Promentum provides boron in the same sugar-bound form found in fruits and vegetables, offering a well-tolerated way to supplement this trace element. Adequate boron intake is associated with normal mineral metabolism and healthy aging of the musculoskeletal system.
Mechanism of action
Food-form boron delivery
Calcium fructoborate is a boro-carbohydrate in which a borate group is diester-bound to two fructose molecules with calcium as counter-ion. This mirrors how boron naturally occurs in plants, and is proposed to be absorbed and utilized differently from inorganic borates like boric acid or sodium borate.
Modulation of inflammatory signaling
In clinical and mechanistic work, calcium fructoborate is associated with lower C-reactive protein, fibrinogen, and pro-inflammatory cytokines (IL-1beta, IL-6, MCP-1). Boron is thought to influence enzymes and signaling pathways governing the inflammatory response within joint tissue.
Support of mineral and vitamin D metabolism
Boron can influence the metabolism of calcium, magnesium, and vitamin D and the activity of steroid hormones. By supporting these pathways, fructoborate may aid bone remodeling and mineral utilization, though the precise molecular targets in humans are still being defined.
Clinical trials
Comparative, double-blind, placebo-controlled study of calcium fructoborate (FruiteX-B/Promentum's active molecule) (Pietrzkowski et al., 2014, Clinical Interventions in Aging). Evidence is on the calcium fructoborate ingredient, consistent with Promentum.
Adults with self-reported knee discomfort
In 60 adults with self-reported knee discomfort, calcium fructoborate (110 mg twice daily) reduced WOMAC and McGill pain scores versus placebo at days 7 and 14, while the placebo group did not change. The study was small, ran 2 weeks, and was conducted by the manufacturer, so results are preliminary.
Double-blind, placebo-controlled pilot in middle-aged people with primary osteoarthritis (Scorei et al., 2011, Biological Trace Element Research). Component evidence on the calcium fructoborate molecule.
Middle-aged adults with primary osteoarthritis (pilot, small sample)
Compared with placebo, calcium fructoborate was associated with reductions in inflammatory markers (including C-reactive protein and fibrinogen) and improvements in some lipid markers. Findings are hypothesis-generating given the small pilot design.
Clinical study measuring C-reactive protein, total cholesterol, LDL, triglycerides, IL-1beta, IL-6, and MCP-1 with calcium fructoborate (Rogoveanu et al., 2015, Biological Trace Element Research). Component evidence on calcium fructoborate.
Healthy adults (30-day blood-biomarker study, not an osteoarthritis population)
In healthy adults, 30 days of calcium fructoborate (56 or 112 mg/day) was associated with lower C-reactive protein, IL-1beta, IL-6, MCP-1, LDL and triglycerides, mostly measured against each person's own baseline. These are blood-biomarker changes, not measured joint or disease outcomes.
Narrative review of fructoborate biochemistry and human health (Hunter et al., 2019, Biological Trace Element Research) plus a controlled rat osteoarthritis model showing Hedgehog/DDIT3 pathway activation (Yan et al., 2025, Biological Trace Element Research). The 2025 data are animal, not human.
Review of human and mechanistic data; rat osteoarthritis model
The review summarizes consistent, generally favorable safety and joint/inflammation signals across small human studies, while the rat study offers a candidate molecular mechanism for cartilage protection that has not yet been confirmed in people.