Chlorophyll drops are the second chlorophyll craze, not the first. In the early 1950s, chlorophyll went into everything, and TIME reported that manufacturers were selling chlorophyll popcorn and chlorophyll-impregnated baby pants. The humorist Richard Armour summed it up in a rhyme, first printed in the Wall Street Journal, asking why the goat on yonder hill, who seems to dote on chlorophyll, still reeks. Even Franklin Howard Westcott, the internist who helped start the fad, complained that too many people had been victimized by that goat.

Most chlorophyll drops today are not plain chlorophyll. According to the Linus Pauling Institute, the common supplement form is sodium copper chlorophyllin, a water-soluble, semi-synthetic version in which copper replaces the magnesium at the center of the molecule. That is why it mixes into water and turns it green.

The evidence is modest. Chlorophyllin has a long history as an internal deodorant, but the institute notes that a placebo-controlled trial found no significant improvement in fecal odor in colostomy patients. It can turn urine or stool green and sometimes upsets the stomach, and its safety in pregnancy is not established, so check with your doctor first.

The first grid is liquid chlorophyll drops. The second is liquid bottles, capsules and softgels. My tip: start with half a serving in a full glass of cold water, and drink it through a straw if you are worried about staining your tongue.

Herbs Etc. ChlorOxygen is the most reviewed drop in this grid, an alcohol-free mint concentrate where 18 drops in water give 50 mg and 36 drops give 100 mg, with 66 servings per bottle and no refrigeration needed. Nature's Way Chlorofresh is the classic, 100 mg of chlorophyllin per 25-drop serving in a mint glycerin base. MaryRuth's is peppermint and derived from mulberry leaves, 50 mg per serving, for ages 14 and up.

Trace Minerals Ionic Chlorophyll is unflavored, 100 mg per serving, made with the brand's Concentrace mineral concentrate and organic glycerin, and third-party tested. NOW Foods Liquid Chlorophyll is an unflavored, extra-strength concentrate, and it ties for the best rating here with Codeage, a vegan peppermint drop with 50 mg per serving that is free of dairy, soy and gluten.

Best Naturals is an unflavored 50 mg drop with 120 servings in a glass dropper bottle. BioSchwartz is an organic, unflavored drop with 118 servings per bottle.

What I would skip: the unflavored drops if you have never tried chlorophyll. Plain chlorophyll can taste grassy, and a mint drop like ChlorOxygen or Chlorofresh makes the first week much easier. Once you know you like the habit, the unflavored ones mix more easily into juice.

NOW Foods Chlorophyll Capsules are the most reviewed product in this edit, 100 mg per capsule with alfalfa powder, one a day, and they tie for the best rating in this grid. Nature's Way Chlorofresh Softgels give 100 mg in two softgels, but they are gelatin and contain soy, so they are not for vegans. Nutricost Softgels are 100 mg per two-softgel serving, third-party tested, and new enough to have no reviews yet. Nature's Craft Chlorophyll Capsules add parsley and peppermint in a gentle-dose formula meant to be easy on the stomach, also without reviews so far.

For liquids, Swanson Liquid Chlorophyll is mulberry-derived, 100 mg per tablespoon, and ties NOW for the best rating. Dynamic Health is a spearmint liquid you mix with water, seltzer or juice. Both need refrigerating after opening. World Organic is unflavored and preservative-free, from alfalfa leaves, with 100 mg per serving, and it is vegetarian and gluten-free. Double Wood Supplements is a mint drop in a 30-day supply, new at the retailer with no reviews yet.

What I would skip: a capsule and a liquid at the same time. Pick one form and one serving a day, and do not stack products to chase a faster result.

I think chlorophyll drops are a nice habit if you enjoy them, not a cure for anything. The best-known use is still odor, and even that evidence is mixed, so buy them for the ritual of a green glass of water and keep your expectations realistic. Choose mint for taste or capsules if you dislike the flavor, and ask your doctor first if you are pregnant or breastfeeding. A daily glass will not make you smell like a meadow. The goat rhyme from the 1950s still applies.