National Senior Citizens Day: Peru's Horsetail Tea

Every August 21st, the U.S. quietly marks National Senior Citizens Day.

Most people mark it with a phone call or a visit. In the Andes, a lot of households mark the years with something simpler: a daily cup of cola de caballo, horsetail tea, the way their grandparents drank it.

What Cola de Caballo Actually Is

Horsetail (Equisetum arvense) is a bristly, jointed plant that grows wild across temperate regions, including the Peruvian highlands, where it's sold in nearly every herb stall as cola de caballo. The name comes from its shape: thin, segmented stalks that fan out like a horse's tail once they mature.

Walk through Lima's Mercado Central and you'll find bundles of the dried plant stacked next to manzanilla and boldo, sold loose by the handful, priced the same modest way it's been sold for decades. Andean herbalists have brewed it for generations, mostly as a mild diuretic and, more specifically, as a plant people reach for as they get older and start paying closer attention to bones, joints, and skin.

Why Silica Gets the Credit

Horsetail is one of the richest plant sources of silica, a mineral the body uses to build collagen. Collagen is the protein that holds cartilage, tendons, and skin together, and levels naturally decline with age. That's the mechanism behind why this plant keeps coming up in conversations about joint comfort and skin elasticity as people get older.

It's not a claim unique to Peru, either. European herbal medicine has used horsetail for the same reason for centuries, and it's one of the few plant sources where silica shows up in a form the body can actually absorb, rather than passing through unused.

What the Research Actually Shows

A small 2015 study published in the Journal of the International Society of Sports Nutrition found horsetail extract supported bone-related markers in postmenopausal women over a 12-week period. Older lab research on horsetail's diuretic effect has also held up reasonably well next to some other traditional diuretics people compare it to.

That's encouraging, but it's still a thin body of research: small trials, not large-scale studies. Nobody should expect horsetail tea to reverse joint damage or replace an actual bone-density treatment. What the evidence supports is more modest: a reasonable, traditional habit worth trying alongside whatever a person's doctor already recommends, not a stand-in for it.

Not Just for Grandparents

The Senior Citizens Day framing fits the tradition, but the plant isn't only for people counting decades. Younger people who train regularly, or anyone dealing with brittle nails or dull hair, reach for the same tea, since collagen support matters at any age once you're asking the body to hold up under repeated stress. It's just that the habit tends to start once joints start announcing themselves a little more.

How Peruvians Actually Drink It

The traditional method is simple. Steep a tea bag or a spoonful of the loose dried herb in hot water for 8 to 10 minutes, longer than most herbal teas, since horsetail's tougher stems need the extra time to release what's in them. It has a mild, slightly grassy taste, closer to green tea than anything medicinal.

Most people who build it into a routine drink one to two cups a day, often earlier in the day, since the diuretic effect can mean an extra trip to the bathroom overnight if you drink it too close to bed. That's a small, practical detail, but it's the kind of thing that decides whether a habit actually sticks.

For anyone building out a joint-comfort routine, our Inflammation & Joint Support collection has a few other traditional options worth pairing with it, and horsetail tea itself is a straightforward place to start.

A Few Cautions

Horsetail contains a compound called thiaminase, which can break down vitamin B1 with heavy or prolonged use, so it isn't meant to be a daily habit that runs forever without a break. It can also interact with diuretic medications and lithium, so anyone taking those should talk to a doctor before adding it. It's not recommended during pregnancy or for anyone with kidney disease, given its diuretic action. As with any herbal tea, more isn't better. The traditional pattern is a cup or two a day, not a substitute for water.

We sell this tea and we've read the research behind it. The honest version is that cola de caballo is a genuinely old habit with a real, if modest, mineral behind it, worth trying for anyone thinking more about bones and joints as the years add up, not a cure for anything on its own.

*These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.