Prostate Supplements for BPH: What Guidelines Say

• Niacin (vitamin B3)

  214% of the upper limit
  1 capsule37.5 mg

  2 capsules (label serving)75 mg

  35 mg a day: the adult upper limit for niacin from supplements (a ceiling, not a target)35 mg

  Printed on the label: 75 mg per 2 capsules. (NIH ODS, Niacin)

• Saw palmetto

  26% of the studied amount
  1 capsule42.2 mg

  2 capsules (label serving)84.5 mg

  320 mg of extract a day in the large prostate trials320 mg

  Printed on the label: 84.5 mg per 2 capsules. (Bent et al., NEJM 2006)

• Ginkgo biloba

  50% of the studied amount
  1 capsule60 mg

  2 capsules (label serving)120 mg

  240 mg of extract a day in a 6-year memory trial240 mg

  Printed on the label: 120 mg per 2 capsules. (DeKosky et al., JAMA 2008 (GEM))

• Tribulus

  30% of the low end of the studied amount
  1 capsule60 mg

  2 capsules (label serving)120 mg

  400-750 mg a day in erection studies400-750 mg

  Printed on the label: 120 mg per 2 capsules. (Vilar Neto et al., Nutrients 2025)

• Vitamin E

  1% of the upper limit
  1 capsule6.5 mg

  2 capsules (label serving)13 mg

  1,000 mg a day: the adult upper limit (a ceiling, not a target)1,000 mg

  Printed on the label: 13 mg per 2 capsules. (NIH ODS, Vitamin E)

Lime bars: what 1 or 2 capsules hold, from the Supplement Facts panel. Cyan bars: daily amounts of that ingredient alone in studies (the pale extension shows a range). Amber bars: the adult upper limit, a ceiling to stay under, not a goal. Niacin is the one line that goes past its limit. No trial has tested Protoflow itself.