Pure Encapsulations OptiFerin-C

Iron is the engine behind your oxygen delivery system. Every red blood cell relies on it to carry oxygen from your lungs to your working muscles, and when iron stores drop, your performance drops with it.

For endurance athletes, the problem is this: training-induced losses through sweat, GI stress, and foot-strike impact can drain your iron faster than diet alone can replace it. Iron deficiency rates in endurance athletes run as high as 20–50% in women and up to 50% in men, making it the number one nutritional deficiency affecting athletic performance.

More Oxygen to Your Muscles, More Energy in Your Legs

Pure Encapsulations OptiFerin-C delivers 28mg of Ferrochel® iron bisglycinate — a patented chelated iron that absorbs rapidly without the GI side effects that make most iron supplements miserable to take.

Fast Absorption, No Stomach Issues – Ferrochel® iron bisglycinate uses patented chemistry that allows iron to pass directly through intestinal walls into your bloodstream. Unlike ferrous sulfate (the cheap iron in most drugstore supplements), Ferrochel® is tightly controlled by your intestinal tissue, which means efficient uptake without the nausea, constipation, and stomach cramping that make athletes dread taking iron.

Supports Healthy Ferritin, Hemoglobin, and Red Blood Cell Function – In a double-blind, placebo-controlled trial, iron supplementation supported healthy ferritin levels and enhanced energy and well-being. Research on elite female athletes emphasizes that maintaining ferritin above 35–50 ng/mL is critical for sustained endurance performance, energy production, and recovery.

Vitamin C Built In for Maximum Iron Uptake – Each capsule includes 100mg of buffered vitamin C (calcium ascorbate), which enhances iron absorption and is gentle on your stomach. No need to time a separate vitamin C supplement — it's already paired for you.

Even without full-on anemia, low ferritin silently impairs your performance. Iron-dependent enzymes drive aerobic metabolism and energy production at the cellular level. When those enzymes are starved for iron, you fatigue faster, recover slower, and rely more on anaerobic pathways, even during efforts that should feel easy.

How to Use Pure Encapsulations OptiFerin-C

Daily dose: Take 1 capsule, 1–3 times daily, with meals.

Timing: Take with meals to maximize absorption and minimize any chance of stomach discomfort. Avoid taking with coffee, tea, or calcium-heavy foods, which can inhibit iron uptake.

Pro tip: Get your ferritin tested every 8–12 weeks during heavy training to dial in your dose. Athletes with ferritin below 35 ng/mL typically benefit from 1–2 capsules daily; those actively rebuilding stores may need the full 3-capsule dose under guidance from their physician.