Let me start by saying this vest is *tight*—like, 'first-time-wearing-it-I-questioned-my-life-choices' tight. I followed the sizing chart (went for Medium as a typical L-shirt wearer) and initially struggled to pull it over my shoulders. Pro tip: Step into it like a skirt instead of wrestling it overhead unless you enjoy impromptu yoga sessions.

The compression is no joke. Within minutes, my 'dad bod' looked noticeably smoother under shirts—no more awkward fabric bunching around the waist. It stays PUT during workouts too; no rolling up when deadlifting or doing burpees. That said, the armpit area felt restrictive for the first week until the material loosened slightly. Now? It’s like a firm hug rather than a chokehold.

Biggest win? Confidence boost. As someone with mild gynecomastia, seeing a flatter chest in dress shirts (even thin linen ones) was game-changing. No visible seams poking through either, though avoid washing it with darks—my white vest now has a 'vintage cream' tint thanks to a laundry mishap.

Downsides? The newer batches seem less compressive based on older reviews (I can’t compare personally). Also, sizing is *wildly* inconsistent—one XXL tag actually fits like an XL. If between sizes, size up unless you want to reenact a sausage casing.

Verdict: Not magic (still hit the gym), but for $25? Worth it purely for that ‘instant slim’ effect under clothes. Just manage expectations—it’s shapewear, not liposuction.