Are insulin-specific coolers worth buying?

Yes, because they keep insulin between 36°F and 46°F without freezing, which regular coolers can’t guarantee. Dedicated medical coolers use phase-change packs for consistent temperature, either evaporative (like Frio) or powered (USB/car). They’re worth it if you travel or live in a hot climate; for short trips, a good insulated bag with a room-temp gel pack is fine. Your insulin is too important to trust to a cooler meant for beer.