De Marchi claims that the Merino Compression Socks are the first all-natural compression socks available. We suspect this is because it's much easier to dial the mmHg of synthetic materials to the level you want. Whatever the case, we're glad that the Italian manufacturer figured out how to make Merino compressive. Merino wool is a great all-weather choice for socks because it vents and insulates, depending on the conditions, and its natural antimicrobial qualities mean, bluntly, that your socks won't stink. Plus, Merino is just about the most comfortable material in sportswear, even with all of the synthetic advances we've been able to enjoy. There's something about pulling on wool that just reassures. Compression is something of a hot topic these days, which we owe to some dubious claims that have been circulating about it. Still, circulation is where compression really shines, as the targeted pressure increases blood circulation in order to maintain a consistent flow of oxygen to your muscles while they're working or recovering. This technique has been used in medical treatment for decades. Compression also stabilizes muscles, reducing the need to compensate for minute vibrations from sources like road noise that can fatigue muscles over time. Think lifting weights on a machine versus lifting free weights. The stabilization of the free weights creates more fatigue. Endurance workouts produce a similar effect, but it's more subtle except over long periods of time.