The 4 Best Iron Supplements of 2026
By Erin Rose Updated October 6, 2026 How we score
The best iron supplement for most people is Nature Made Iron 65 mg: 65 mg of iron in one tablet for $0.06 a day, on Informed Choice + USP Verified. Take it only if a blood test shows you are low: 65 mg is over NIH’s 45 mg daily limit for healthy adults, so it is a dose for treating low iron, not a daily habit.
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Our picks at a glance
Our pick for: Most people who need iron
Nature Made Iron 65 mg
9.0/10 Our score
9.0/10, the top score of the 8 standard iron tablets we score
Good
- On the Informed Choice and USP Verified lists (checked October 5, 2026)
- Treatment dose: 65 mg per serving (we count 40 mg or more)
- Label states the amount, with no blend
Watch for
- Costs 1.3 times as much per dose as the cheapest of its kind we score
- Iron
- 65 mg a tabletfrom 325 mg ferrous sulfate
- A day
- $0.061 tablet, brand list price
- Testing list
- Informed Choice + USP Verified
- Form
- Ferrous sulfatethe standard form
- Bottle
- 180-tablet bottle, $10.59Nature Made’s own store
- Per 60 mg
- $0.0541.3x the cheapest
Our take
Why we pick it Doctors’ guidelines say no form of iron works better than another (AGA 2024), and this is the standard one: 65 mg of iron a tablet, close to the 60 mg used in the iron-absorption trials. It is on Informed Choice + USP Verified, which check that the tablet holds what the label says, and it costs about 6 cents a day at list price.
What you give up Comfort. In 20 trials against a placebo, ferrous sulfate more than doubled the odds of stomach side effects such as nausea and constipation (Tolkien 2015). Two fixes: take it every other day, or switch to our gentler pick.
One more thing 65 mg is above the 45 mg daily upper limit NIH sets for healthy adults. That limit is about side effects in people who are not low; take a treatment dose like this when a blood test shows low iron, and have the test repeated. How much iron to take.
Testing record
- Informed Choice: banned substances, monthly retail samples Checked October 5, 2026.
- USP Verified: contents and purity Checked September 22, 2026.
Not found on: NSF Certified for Sport, Informed Sport, NSF/ANSI 173.
Our other 3 picks
Each is for a different need: a gentler form, drug-tested sport, or a small daily top-up. None of them is a full treatment dose in one pill.
- Gentler on the stomach Thorne Iron Bisglycinate 25 mg
- You are drug-tested in sport Klean Athlete Klean Iron 27 mg
- A low-dose top-up OLLY Delightful Iron 18 mg chewable
Our pick for: Gentler on the stomach
Thorne Iron Bisglycinate 25 mg
6.5/10 Our score
6.5/10, tied for #2 of the 15 chelated (bisglycinate) irons we score
Good
- On the NSF Certified for Sport and NSF/ANSI 173 lists (checked October 5, 2026)
- Label states the amount, with no blend
- No FDA recall for the brand in 24 months
Watch for
- Below a treatment dose: 25 mg per serving (we count 40 mg or more)
- Costs 3.6 times as much per dose as the cheapest of its kind we score
- Iron
- 25 mg a serving1 capsule
- A day
- $0.27one serving, brand list price
- Testing list
- NSF Certified for Sport + NSF/ANSI 173
- Form
- Iron bisglycinate (Ferrochel)gentler on the stomach in trials
- Bottle
- 60-capsule bottle, $16.00Thorne’s list price
- Per 60 mg
- $0.643 servings
Our take
25 mg of iron as bisglycinate, a chelated form, on NSF Certified for Sport + NSF/ANSI 173. In trials in pregnant women, bisglycinate caused fewer stomach complaints than other iron salts (Fischer 2023), and 25 mg of it worked as well as 50 mg of ferrous sulfate to prevent low iron (Milman 2014). It costs $0.27 a capsule at list price.
Testing record
- NSF Certified for Sport: banned substances, by lot See the listing Checked October 5, 2026.
- NSF/ANSI 173: contents match the label Checked October 5, 2026.
Not found on: Informed Sport, Informed Choice, USP Verified.
Our pick for: You are drug-tested in sport
Good
- On the NSF Certified for Sport and NSF/ANSI 173 lists (checked October 5, 2026)
- Label states the amount, with no blend
- No FDA recall for the brand in 24 months
Watch for
- Below a treatment dose: 27 mg per serving (we count 40 mg or more)
- Costs 11.2 times as much per dose as the cheapest of its kind we score
- Iron
- 27 mg a serving1 tablet
- A day
- $0.21one serving, brand list price
- Testing list
- NSF Certified for Sport + NSF/ANSI 173
- Form
- Carbonyl iron (Ferronyl)screened for drugs banned in sport
- Bottle
- 90-tablet bottle, $19.00Klean Athlete’s list price
- Per 60 mg
- $0.473 servings
Our take
27 mg of iron (carbonyl iron) a tablet, on NSF Certified for Sport + NSF/ANSI 173: NSF screens it for drugs banned in sport. $0.21 a tablet at list price, the cheapest a serving of the iron screened for drugs banned in sport. Thorne, above, is on NSF Certified for Sport too.
Testing record
- NSF Certified for Sport: banned substances, by lot See the listing Checked October 5, 2026.
- NSF/ANSI 173: contents match the label Checked October 5, 2026.
Not found on: Informed Sport, Informed Choice, USP Verified.
Our pick for: A low-dose top-up
OLLY Delightful Iron 18 mg chewable
7.0/10 Our score
7.0/10, the top score of the 2 other forms we score
Good
- On the NSF/ANSI 173 list (checked October 5, 2026)
- Close to the lowest cost per dose (1.1 times the cheapest of its kind we score)
- Label states the amount, with no blend
Watch for
- Below a treatment dose: 18 mg per serving (we count 40 mg or more)
- Iron
- 18 mg a serving2 tablets
- A day
- $0.47one serving, brand list price
- Testing list
- NSF/ANSI 173
- Form
- Ferric saccharate (microencapsulated)a daily-need dose, not a treatment dose
- Bottle
- 60 chewable tablets tub, $13.99OLLY’s list price
- Per 60 mg
- $1.554 servings
Our take
18 mg of iron in 2 chewable tablets, the daily need for women 19 to 50 (NIH), on NSF/ANSI 173. For topping up when you eat little meat or have heavy periods but have not been tested low. $0.47 a day at list price. It is not a treatment dose.
Testing record
- NSF/ANSI 173: contents match the label Checked October 5, 2026.
Not found on: NSF Certified for Sport, Informed Sport, Informed Choice, USP Verified.
Which one is for you?
| Your situation | What to buy |
|---|---|
| A test showed low iron | Nature Made Iron 65 mg, one tablet a day or every other day, $0.06 a day (our pick) |
| Iron upsets your stomach | Thorne Iron Bisglycinate 25 mg, $0.27 a day (above) |
| You are drug-tested in sport | Klean Athlete Klean Iron 27 mg, $0.21 a day (above) |
| You want a small daily top-up | OLLY Delightful Iron 18 mg chewable, 18 mg in 2 chewable tablets, $0.47 a day (above) |
| You are vegan | Momentous Iron+ 25 mg, labeled vegan, on NSF Certified for Sport + NSF/ANSI 173, $0.33 a day |
| Price matters most | Nature's Bounty Iron 65 mg, the same 65 mg tablet as our pick for less, $0.05 a day. It is not on a public testing list. |
Should you take iron every day?
Every other day works as well, with fewer stomach problems. In iron-depleted women, a 60 mg dose taken every other day was absorbed better than the same dose taken daily (Stoffel 2017). In a later trial, every-other-day iron built the same iron stores with fewer stomach side effects (von Siebenthal 2023). When to take iron.
Every pick is on at least one public testing list (NSF, USP or Informed). Which iron is on which list, with screenshots.
| Item | Value |
|---|---|
| Nature's Bounty Iron 65 mg | $0.042 |
| Nature Made Iron 65 mg | $0.054 |
| Piping Rock Iron 65 mg | $0.064 |
| Piping Rock Slow Release Iron 45 mg | $0.087 |
| Klean Athlete Klean Iron 27 mg | $0.47 |
| Thorne Iron Bisglycinate 25 mg | $0.64 |
| Momentous Iron+ 25 mg | $0.80 |
| OLLY Delightful Iron 18 mg chewable | $1.55 |
Where we disagree with the big guides
Fortune names Ritual Iron its best overall, a 60 mg bisglycinate it marks as third-party tested. We found Ritual Iron on none of the public testing lists; Ritual’s multivitamin, magnesium and protein powders are on them. Fortune’s pick for anemia, Nutricost Iron for Women, is on none of them either.
Garage Gym Reviews names Thorne Iron Bisglycinate its best overall and Nature Made Iron 65 mg its budget pick. We pick the same two, in the other order: for someone a test has shown to be low, the standard tablet gives more iron per dollar, and guidelines say no form works better. Its “GI-friendly” pick, Slow Fe, is ferrous sulfate in a slow-release tablet; it is on no public list we search and costs $0.42 per 60 mg, against $0.054 for our pick. We read both guides on October 6, 2026.
The 8 we show, out of the 34 we score, and how we checked them
| Product | Score | Iron | Per 60 mg | Testing list | Bottle and list price | Buy |
|---|---|---|---|---|---|---|
| Nature Made Iron 65 mgNature Made · standard tablet · ferrous sulfate (325 mg) | 9.0/10 | 65 mg1 tablet | $0.054 | Informed Choice, USP Verified | 180-tablet bottle, $10.59 | Buy on Amazon |
| Piping Rock Iron 65 mgPiping Rock · standard tablet · ferrous sulfate | 9.0/10 | 65 mg1 tablet | $0.064 | NSF/ANSI 173 | 250-tablet bottle, $17.29 | Buy on Amazon |
| Piping Rock Slow Release Iron 45 mgPiping Rock · standard tablet · ferrous sulfate, slow release | 8.0/10 | 45 mg1 tablet | $0.087 | NSF/ANSI 173 | 200-tablet bottle, $12.99 | Buy on Amazon |
| OLLY Delightful Iron 18 mg chewableOLLY · other form · ferric saccharate (microencapsulated) | 7.0/10 | 18 mg2 tablets | $1.55 | NSF/ANSI 173 | 60 chewable tablets tub, $13.99 | Buy on Amazon |
| Nature's Bounty Iron 65 mgNature's Bounty · standard tablet · ferrous sulfate (325 mg) | 7.0/10 | 65 mg1 tablet | $0.042 | Not found* | 100-tablet bottle, $4.54 | Buy on Amazon |
| Klean Athlete Klean Iron 27 mgKlean Athlete · standard tablet · carbonyl iron (Ferronyl) | 6.5/10 | 27 mg1 tablet | $0.47 | NSF Certified for Sport, NSF/ANSI 173 | 90-tablet bottle, $19.00 | Buy on Amazon |
| Thorne Iron Bisglycinate 25 mgThorne · chelated (bisglycinate) · iron bisglycinate (Ferrochel) | 6.5/10 | 25 mg1 capsule | $0.64 | NSF Certified for Sport, NSF/ANSI 173 | 60-capsule bottle, $16.00 | Buy on Amazon |
| Momentous Iron+ 25 mgMomentous · chelated (bisglycinate) · iron bisglycinate (Ferrochel) · also vitamin C 50 mg, B vitamins | 6.5/10 | 25 mg1 capsule | $0.80 | NSF Certified for Sport, NSF/ANSI 173 | 60-capsule bottle, $19.99 | Buy on Amazon |
* Not found on the public NSF, USP or Informed lists (searched September 22, 2026 to October 5, 2026).
The score. Five marks: does a serving give at least 40 mg of iron, which we count as a treatment dose (the iron-absorption trials used 60 to 100 mg; this line is ours, not an official one); is the product on a public testing list (a brand’s own testing claim, with no listing, earns half the 3 points); what 60 mg of iron costs against the cheapest in its group; does the label state the amounts; and any FDA recall naming the brand. Dose and testing are worth up to 3 points each, cost up to 2, label and recalls up to 1 each, for 10 in all. Scores rebuilt October 6, 2026. How we score.
Not scored, and why.
- Lifeable Kids Iron Gummies 10 mg with Vitamin C: A children's product. The iron pages cover adults.
- Enfamil Fer-In-Sol Iron Drops: Infant drops. The iron pages cover adults; give iron to a baby only on a pediatrician's advice.
- Proferrin ES heme iron 10.5 mg: Heme iron is absorbed by a different route, so its milligrams do not compare with the other iron here. Proferrin Clear is on NSF/ANSI 173, but it was out of stock (October 6, 2026); Proferrin ES is not on a list.
- up&up Iron 65 mg (Target): On NSF/ANSI 173, but sold only at Target, not on Amazon, so we cannot link it.
What iron does, and what to watch for
Iron helps people who are low. In 198 women with fatigue, ferritin under 50 and no anemia, 80 mg of iron a day for 12 weeks cut fatigue scores by 48%, against 29% on a placebo (Vaucher 2012). How often to take it is above.
Vitamin C is a split call. A 2024 guideline for doctors says to add it (AGA 2024); a 2023 review found it did not clearly raise hemoglobin or ferritin, with very low-quality evidence either way (Loganathan 2023). Your body loses very little iron, so extra can build up, and iron pills are dangerous to young children: keep them out of reach. Our dosage guide covers how much to take.
More: ferrous sulfate vs bisglycinate, when to take iron, which iron is third-party tested and how common low iron is.
Sources
- DeLoughery TG, et al. AGA Clinical Practice Update on Management of Iron Deficiency Anemia: Expert Review. Clin Gastroenterol Hepatol. 2024. PubMed 38864796
- Tolkien Z, et al. Ferrous sulfate supplementation causes significant gastrointestinal side-effects in adults: a systematic review and meta-analysis. PLoS One. 2015. PubMed 25700159
- von Siebenthal HK, et al. Alternate day versus consecutive day oral iron supplementation in iron-depleted women: a randomized double-blind placebo-controlled study. EClinicalMedicine. 2023. PubMed 38021373
- Stoffel NU, et al. Iron absorption from oral iron supplements given on consecutive versus alternate days and as single morning doses versus twice-daily split dosing in iron-depleted women. Lancet Haematol. 2017. PubMed 29032957
- Fischer JAJ, et al. The effects of oral ferrous bisglycinate supplementation on hemoglobin and ferritin concentrations in adults and children: a systematic review and meta-analysis. Nutr Rev. 2023. PubMed 36728680
- Milman N, et al. Ferrous bisglycinate 25 mg iron is as effective as ferrous sulfate 50 mg iron in the prophylaxis of iron deficiency and anemia during pregnancy. J Perinat Med. 2014. PubMed 24152889
- Vaucher P, et al. Effect of iron supplementation on fatigue in nonanemic menstruating women with low ferritin: a randomized controlled trial. CMAJ. 2012. PubMed 22777991
- Loganathan V, et al. Treatment efficacy of vitamin C or ascorbate given as co-intervention with iron for anemia: a systematic review and meta-analysis. Clin Nutr ESPEN. 2023. PubMed 37739692
- Ko CW, et al. AGA Clinical Practice Guidelines on the Gastrointestinal Evaluation of Iron Deficiency Anemia. Gastroenterology. 2020. PubMed 32810434
- NIH Office of Dietary Supplements. Iron fact sheet for health professionals (updated September 4, 2025; read October 6, 2026).
- Other guides, read October 6, 2026: Fortune, “Best iron supplements” (updated October 4, 2026) and Garage Gym Reviews, “Best Iron Supplement” (updated September 8, 2025).
- Labels: each brand’s page or the NIH Dietary Supplement Label Database. Testing: NSF/ANSI 173, NSF Certified for Sport and Informed Choice, read October 5, 2026; Informed Sport and USP Verified from our copies of September 22, 2026 (USP’s site blocks automated reads). Recalls: openFDA. Prices: each brand’s own list price (iHerb or Walgreens where named), checked October 6, 2026.