Ferrous bisglycinate: the iron that is gentle

If iron is on your label, people ask two things: will it upset my stomach, and what does it do to labs.

Here is how we chose 18 mg ferrous bisglycinate + 5 mg BioPerine®, why we say with food, and what the predictable effects actually mean.

What does "gentle" actually mean for iron?

Ferrous bisglycinate is a chelated iron, iron bound to the amino acid glycine, that is well absorbed and usually kinder to the stomach than oxide or sulfate at the same elemental amount.

BioPerine® (black pepper fruit) is the small amplifier: 5 mg that helps co-taken iron count a little more.

Iron can still be noticeable for some people on some days, which is normal. A chelate is chosen to make that less likely, and taking it with a meal helps too.

Why 18 mg of iron?

• It is enough to matter for ferritin and daily energy without being a mega-dose.
• It sits below the common tolerable upper intake discussion points people cite for long daily use, while still being a therapeutic-ish amount for many adults who run low.

Your clinician and your labs decide whether you need more, less, or none. Iron is not a guess.

What is the one predictable effect of iron?

Iron darkens stool. Black stool on iron is expected and harmless in itself. If black stool comes with pain, vomiting, or dizziness, that is always a "see your clinician now" sign, iron or not.

Why must iron be taken with food?

Take Keel with a meal that has substance. Iron is kinder there, the enzymes have something to work on, and you are less likely to feel the mineral on a tight stomach.

Why does the bottle say keep away from children?

Accidental iron overdose is dangerous for young children. Keep the bottle out of reach and never describe iron as candy or as a kids' product.

Where does iron sit on Keel's label?

Nutrient	Amount	Form
Iron	18 mg	Ferrous bisglycinate
BioPerine®	5 mg	Black pepper fruit
Vitamin B12	525 mcg	Methylcobalamin
Folate	400 mcg DFE	L-5-MTHF-Ca
Vitamin B6	26 mg	P5P

Same label, same bottle: Keel, two caps a day, with food. If you want the whole minerals lane, pair this with the magnesium + zinc piece.

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The wider picture is in our guide to eating and supplementing well on GLP-1 medications.

FAQ

Should I add a separate iron? Not without a lab. Keel has 18 mg. Doubling without ferritin or a clinician's plan is not cautious.

What about B12 and folate with iron? Keel's methylated B12 (525 mcg methylcobalamin), 400 mcg folate L-5-MTHF-Ca and 26 mg P5P sit in the same bottle so you are not juggling three more labels. Still tell your clinician what you take.

Is black stool always harmless? On its own, yes, iron reliably does this. Paired with pain, vomiting or dizziness it stops being a cosmetic effect and becomes a reason to see your clinician.

Sources

• NIH Office of Dietary Supplements, Iron fact sheet
• Shoba et al., Influence of piperine on the pharmacokinetics of curcumin in animals and human volunteers, Planta Medica

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.