They're EXCLUSIVELY B12, and don't claim to pack an entire B-complex into a 3/4×3/4 inch colorless sticker. Effectiveness matters to me, and these are an excellent choice. Many patches don't declare which form of B12, or they use cyanocobalamin, an inactive form that people with MTHFR issues may not assimilate at all. Methylcobalamin is more expensive, but its effectiveness is SIGNIFICANTLY more reliable.I have a SEVERE B12 deficiency. I get weekly hydroxycobalamin injections, and I get 4-5 days out of them before I'm crashing again.I've tried all supplemental forms of cobalamin, in lozenges, sprays, drops. Other patches, too.This one is different. I get all the way to my next injection before my brain abandons me and my body feels like lead.The active side of this patch is actually red, like any injectable cobalamin. It comes in individual light-blocking pouches. The adhesive substrate is more gel-like than duct-tape-like.I didn't measure, but they're about 1×1.5 inches and tan on the outside, so not tiny, but not big or obvious. I've seen poor reviews about their adhesive, and I guess it depends a lot on where you stick them. It's true, an arm that has hair or sees a lot of friction isn't going to work, but on a hip, chest or belly they seem to do fine. Yes, it would be nice if they were a little stickier, but it's a day-patch. It doesn't need to stay on for a week.UPDATE: I've used this patch and another SEEMINGLY "stickier" patch for a couple months, and I can tell you that of the two, THIS is the one that stays in place. The materials form to your skin and have about the same stretchiness as skin, where with other brands, the edges consistently peel up and hang up in clothing. This is far superior stickiness.