Are these medical-grade compression socks?

No. They are support socks with mild graduated compression from the ankle up. If you need a prescribed pressure level, buy a measured medical stocking instead.

How do alpaca socks compare with merino?

Alpaca is warmer and softer against the skin, and it does not prickle like wool. Merino handles sweat and repeated washing better, so pick merino for sport and alpaca for cold, dry days.

How should I wash them?

Wash at 30 degrees on a gentle cycle and air dry. Heat and tumble drying shrink alpaca and relax the elastane, which loosens the compression.

What size should I pick?

The listed size is M. Check the brand's size chart against your shoe size before ordering, since compression fit depends on foot and calf measurements, not just length.

Will they stay up during the day?

The 6% elastane and crew height are designed to keep them in place on the calf. Owners of similar alpaca support socks report they hold well but relax if washed hot.