Several people use an iron supplement to improve their energy levels and suggest it to others too who have iron deficiencies.

Iron is an essential nutrient that supplies the building blocks for red blood cells, which transport oxygen from your lungs to the rest of your body.

If your iron levels are low–as they are for a huge swath of the population–you can suffer fatigue, reduced aerobic fitness, and a host of other negative side effects.

This is where iron supplements come in. An iron supplement can deliver a concentrated dosage of iron, ideally in a highly absorbable form, to rectify your low iron levels.

However, not all iron is created equal. Some forms of iron are better absorbed than others, and some forms are less likely to result in negative side effects.

Our researchers looked into the iron supplements on the market and identified the best.

1. Best Overall: Ferrosom Iron Supplement by Siba Pharm– Liposomal Dietary

This pill uses a different form of iron than other supplements on the list—It is a gluten-free nutritional supplement, what makes it different than others is that apart from Folic acid, vitamin C and vitamin B12; Ferrosom also contains liposomal iron which is currently believed to be the most superior type of iron, administered to the cells of the body through the liposomal technology, this provide faster results in treating anemia than any other regular iron.

Best review: Unlike similar products on the market, the Ferrosom iron pills avoid most side effects such as constipation, nausea, vomiting, unpleasant after-taste and upset stomach.

One pill contains 360 percent of your daily recommended dose of iron.

Best price on Amazon: https://amzn.to/2ZDKGzW

2. EZ Melts Iron

For those who have certain diet restrictions like being vegan or having allergies to milk, nuts, and soy—finding a supplement that meets all these criteria can be tough. That is where this dissolving tablet comes into play.

Your body needs vitamin C to help absorb any iron you take in, and this supplement includes enough of both nutrients to increase your vitamin and mineral levels. Unlike other supplements, you pop this one in your mouth and simply let it dissolve—no swallowing big pills necessary. Reviewers rave that it tastes great, too, thanks to its orange flavoring.

The product is also free from common allergens like milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, and soy. So most people should be able to take it, no matter your dietary restrictions.

Best price on Amazon: https://amzn.to/2ZDKGzW

3. Best for Vegetarians: Pure Encapsulations Iron-C Hypoallergenic Supplement

Manufactured in Massachusetts, Pure Encapsulations makes sure all its products are GMO-free. You won’t find artificial sweeteners or colors, coatings (making it vegan- and vegetarian-friendly), gluten, magnesium stearate (a common inactive ingredient in iron supplements), or hydrogenated fat in these pills. All you get is iron glycinate and vitamin C in the form of absorbic acid, as well as a cellulose (or plant-fiber) capsule.

Other major allergens like wheat, peanuts, and eggs are also left out of this pill, which the label suggests taking with a meal. You’ll get 60 capsules, each containing 15 milligrams of iron, in one bottle.

Best price on Amazon: https://amzn.to/2ZDKGzW