Ok they do work but I find them very awkward and messy to use.
The active ingredient in this is kiehl's superbly efficient deo/anti perspirant, but at 25% as opposed to 16%. I've used kiehl's and it works--I bought it even after I quit working there, despite the exorbitant price, so that should tell you something. I found this product on a dusty shelf at rite aid (I imagine it'd been there since the Reagan era,) $7.99 for 75 drenched cotton pads. Thankfully the jar was sealed, and they weren't dry. After a week's use, I can tell you I'll be ordering this if I can't find it in a store, it's that effective.
Certain-dri saved me from embarrassment in my youth (I suffer from hyperhidrosis, and if you have it, you know how awful it is,) but I had issues with it losing efficacy over time and starting to smell wonky in the bottle sometimes, like old BO. Adding kiehl's to my certain-dri regimen helped, but it's sooo expensive and not readily available in my area. 5 day seems to be a great solution--the pads are tossed after one use, so there's no fear of a bottle going bad, it's cheap, and it's effective. Plus, I can use it on other areas prone to sweating, like my feet (gross I know, but I'm trying to be helpful.) If you've ever known the fear of raising your arms in public, even in the dead of winter, I suggest giving this product a try. It works.
I agree with the other posts--this stuff is AMAZING. I'm in showbusiness and have ruined many costumes with my sweat. Yuk. This keeps me fresh even after 90 minutes under stage lighting, and my costumes are thanking me. There's nothing else on the OTC market that even comes close. It's hard to find--I get mine online. I hope they never discontinue it!
For all the hyperhidrosis (hyhi) ladies out there, this is as good as it gets. Don't for a moment be fooled by the name "5 Day", which initially frightened me - this is meant to be used every day in place of your regular anti-p.
It comes in a jar of 75 pads soaking in fluid, like polish remover pads, and you can make it last longer by adding your own pads to apply the remaining product once you've run through the 75.
Very sanitary, but having to touch it every day dries the heck out of my fingers. Wash your hands and moisturize after you use this.
It's amazingly effective, with 25% Aluminum Chlorohydrate - all-natural girls take heed - the highest concentration available in any OTC product.
My hyhi seems to be getting worse as I age, and this stuff just barely keeps it under control, but that's saying a LOT. I'm afraid I'm going to have to give in and get botox again, which if done right is a very effective treatment for underarm hyhi (the shots have to go deeper than cosmetic botox, make sure your doc has done it for this reason before, or you'll just get sweaty but wrinkle-free pits :).
But before you give in to the needle, or god forbid the surgery, make an effort to track this down. I have to find it on the net, as no drugstores carry it around here.
Quick note on botox for hyhi; this is extremely effective if done properly. It paralyzes the nerves that stimulate sweat production, and about a week after injections, my pits go from disastrous to bone-dry for at least 6 months. The more you do it, the longer it lasts. It's heaven-sent for this condition, but it's still not reimbursable as it's considered cosmetic (grrr). Make sure you're seeing a doctor who understands botox for hyhi, and has done it before - the application is totally different, much deeper and more of it. It hurts, but it's only 7 minutes or so of pain.
This is everything I had hoped Certain Dri would be, but wasn't. This can be used right after showering, and keeps me fresh and dry for hours, even if I am stressed, overheated, and jittery from caffeine. Unlike Certain Dri, it does not ever irritate my underarms. And it keeps my feet drier than anything else under the sun...not 100% sweat free, but closer to it than Certain Dri or even the very pricey AP product from Dermadoctor. WIN. I got mine at Rite Aid...75 pads for less than $8. Each pad has enough product to cover both underarms.