When U Beauty founder Tina Craig rolls out a product, it is intentionally slow, steady, selective and serious. That’s why her first foray into the body category, the The SCULPT Arm Compound (starting at $58), took three years and 30 rounds of testing to get “just right.” And, you can actually try it yourself if you’re one of the lucky ones to snag this week’s BeautyPass Free Gift Friday. (Click here to sign up for BeautyPass if you haven’t already).

Joining the ranks of Craig’s super popular retinol-fueled Resurfacing Compound, SCULPT was formulated by chemists after Craig requested cooking up her dream product of invisible “shapewear for the arms,” and is designed to “visibly tighten” the skin via an active-rich mix of peptides, plankton and probiotics. “Arm skin has very few sebaceous glands,” she explains. “This means it’s highly susceptible to dehydration, and because of its relatively low oil content, arm skin has a tendency to develop a loose or crepey appearance—regardless of one’s age or size. Furthermore, the arms’ delicate composition makes it one of the first areas of the body to show signs of aging.”

The rich, hydrating and totally nonsticky serum (you can also use it on your neck, hands and décolleté) possesses two proprietary SIREN Capsules packed with antioxidants and retinol, which the company claims “deliver contouring to areas of the skin that need it most, and optimize normal cell turnover to reveal brighter, smoother and firmer-looking skin.” They also work to oxygenate the skin and minimize the accumulation of stagnant fluid underneath it, resulting in a depuffing effect and tighter-looking appearance.

While Craig doesn’t claim that the serum will serve as a substitute for the gym, she does have the clinical trials to back up the fact that, when users combined SCULPT with daily exercise, they saw more than double the results in visible firming as compared to the group who only exercised or used the product as a standalone. These are more compelling stats from the study: After 30 days of use, participants experienced up to a 48-percent increase in skin elasticity, which was measured in the lab. There was also a 167-percent increase in collagen expression and a 242-percent increase in elastin expression.

You can use SCULPT in the morning or at night, but if you’re going to be out in the sun, make sure to apply sunscreen on top, as it does contain retinol, which can sensitize skin to UV damage.