How It Works

Increases free testosterone by reducing SHBG (sex hormone-binding globulin) → more unbound, bioavailable T. Reduces estradiol. Increases vitamin D half-life. Anti-inflammatory via reduced TNF-α and CRP.

Dosage & Timing

Dosage Guide

Daily Dose3-10 mg

TimingDaily with food. 6mg most common studied dose. Cycle: 2 weeks on/1 week off recommended by some.

BioavailabilitySodium tetraborate and boron citrate both well-absorbed (~90%). Take with water, not with high-calcium meal (slight competition).

Optimal Timing

Take with food. Consistency matters more than timing for most supplements.

Cycling & Duration

No cycling required — safe for continuous daily use.

Best Forms (Ranked)

Boron Citrate — ★★★★★

Good absorption. Most common form. Our top pick.

Sodium Tetraborate (Borax) — ★★★☆☆

Very cheap but easy to overdose. Not recommended for supplementation.

Calcium Fructoborate — ★★★★☆

Plant-based form. Good for inflammation. More expensive.

Evidence-Based Benefits

28% increase in free testosterone (6mg/day, 60 days)
39% decrease in estradiol
Reduced SHBG by 9%
Improved vitamin D status
Reduced inflammatory markers (CRP, TNF-α)

Side Effects & Safety

Nausea at >10mg/day
Hormonal effects at very high doses (>20mg)
Accumulates with long-term high dosing

✅ Good For

Men with low free T (especially if total T normal)
Bone health
Arthritis/joint inflammation
Vitamin D supplementation (enhances retention)

⚠️ Skip If

Pregnancy
Hormone-sensitive cancers (consult oncologist)
Already high boron intake (unlikely)

Stacks Well With

Vitamin D3 Magnesium Zinc Ashwagandha

💊 Boron