What 100 Teens and 3 Days Taught Us About Beauty Routines

100 teen girls. 3 days. A different beauty routine.

That's the whole setup of a study we keep coming back to. It's not a scare story, and we're not going to turn it into one. But it raises a question we think every beauty lover deserves to ask: how much say do you really have in what goes into the products you use every day?

The study

In 2016, researchers at UC Berkeley published the HERMOSA study in Environmental Health Perspectives. HERMOSA stands for Health and Environmental Research on Makeup of Salinas Adolescents.

Here's how it worked:

1. 100 teenage girls in Salinas, California took part. The study was youth-led: teens from the community helped design and run it.
2. Researchers measured biomarkers in urine samples: traces showing exposure to certain chemicals commonly used in personal-care products (phthalates, parabens, triclosan and oxybenzone).
3. For 3 days, the girls swapped their usual products for ones labeled free of those chemicals.
4. Then they measured again.

What they found

After just 3 days, several exposure biomarkers dropped significantly.

The researchers were clear that the picture wasn't perfectly tidy. Two other parabens (ethyl and butyl) actually rose slightly, though levels were low and often undetectable. And the study measured exposure, not health outcomes.

So here's the honest takeaway: this isn't proof that cosmetics are dangerous. It's evidence that the products you choose change what you're exposed to, and that the change can happen fast.

It made us wonder

The girls in the study didn't overhaul their lives. They just changed what was on their bathroom shelf, and the results showed up in days.

Which got us thinking. The beauty industry gives you thousands of products, but almost no say in how any of them are made. You pick from what's on the shelf. You read labels you can't always decode. You take the shade, the texture and the formula someone else decided on.

What if you had more control over the beauty products you use?

Make your own beauty

That's the idea behind Pottle. Pottle lets you mix, customize, store and refill your own cosmetics, so the product fits you instead of the other way around.

• Your formula. Start from a base and build what you actually want to put on your skin.
• Your color. Blend the exact shade you're after, not the closest one on the rack.
• Your routine. Store it, refill it, and tweak it whenever your needs change.

The beauty industry gives you thousands of products. Pottle gives you the ability to create your own.

Beauty shouldn't be one-size-fits-all

Three days was enough to show that what we choose matters. Imagine what's possible when you're the one doing the choosing from the start.

Mix. Refill. Repeat.

Discover Pottle

Sources

• Harley KG, Kogut K, Madrigal DS, Cardenas M, et al. Reducing Phthalate, Paraben, and Phenol Exposure from Personal Care Products in Adolescent Girls: Findings from the HERMOSA Intervention Study. Environmental Health Perspectives, 2016.
• UC Berkeley CERCH: HERMOSA Study