Buy a lot of it
This is powerful, long lasting, expensive stuff. That being said, I have used other repellants but won't use them anymore.
I've used this in Southeast Asia during the rainy season and also in the Sierra's in California during springtime, the time when the buggers are out and about the most. I've been through hordes of mosquitoes and came out untouched because of this stuff. I can tell you what sets this apart from the others. It lasts a long time. There's a unique formulation that releases the DEET slowly. Maybe 12 hours more or less, but I sometimes forget to re-apply and it still protects, unlike other products that last only 4 hours and reminded by a nice BITE mark. Also, if I happen to miss a spot, mosquitoes don't remind me I missed it like with other products. Back of the legs, triceps, throat, and ears come to mind. And, with other products, there are some big hungry, daring mosquitoes that bite me anyway (huge bite marks) but not with 3m Ultrathon. They seem to hate this stuff with a passion. If they sold it in bigger tubes I'd buy it, even it means spending 20 - 30 dollars on it.
Make sure you slather it on though, I know it costs a lot but don't go sparingly, use a big splotch and you won't be sorry.
Still my favorite for on-skin use
I just wrote a more detailed review for the Natrapel Picaridin.
Bottom line: I still rely on and prefer this 3M Ultrathon for use on my exposed skin. It WORKS. It LASTS. I can use so little of it, I don't smell it or taste it. (The Natrapel spray had an annoying scent and an "aftertaste" when it got absorbed through my skin.)
I repackage the Ultrathon in very tiny bottles and this can last me weeks, as I only use on my face and fingers.
Only con: I have to be careful with the Ultrathon so I don't damage all the synthetic items I have on/around me. (From what I understand, with the minimal amount of DEET I actually have to use, I believe taking acetamenophin is overall "worse" for me.) Been using DEET (sparingly) for years, and so far, no bad "lab" results on liver health. Knock on wood.
My current protection scheme: Sawyer Permthrin-sprayed clothing. Natrapel spray on clothing hot-spots: gloves, shoulders, arms, hips. Ultrathon on exposed skin (face, fingers). Sea-to-Summit headnet when they physically fly into my face, nostrils, eyes, mouth. Yick.
As an avid mountain biker in New England I need a bug repellent that will keep the mosquitoes and ticks at bay on a long sweaty ride. I've tried many sprays and lotions and in general lotions stand up to sweat much better than sprays. The key is to rub it in - don't just let it evaporate. The sweat resistance of this stuff is impressive. When the mosquitoes are really bad they will bite me through my clothes leaving the treated exposed flesh untouched proving its effectiveness. However, like any DEET product it only works on mosquitoes and ticks. REI's Jungle Juice Plus had a fly repellent that worked pretty well. Too bad they don't sell it anymore :( AS far as being greasy, sure it is a little (it is water resistant after all) but it comes off with a little water and a dry towel. You should always wipe off any bug repellent off your hands anyway.
The high price means I only use this stuff on long hikes and mountain bike rides. For just lounging around I use a cheaper spray.
I LOVE this product! I was camping in the U.P. in Michigan and my boyfriend wanted to teach me how to fly fish... I was very nervous about the large population of little buggers in the small rivers. There were so many that the air had a constant buzzing noise... to my relief I rubbed this stuff right on and didn't get bit once!!! It made my whole camping experience that much better! I will never use another bug repellent! A little bit annoyed that the repellent was on my hands and I accidently put a finger in my mouth... ew... and when i washed it off the palm of my hands the little pests started to take interest so I had to apply more... oh well i guess it would be the same with any product though...
Nice compact size for your backback
Spent 6 days in an adventure camp in Fresno, CA. I could see the mosquitoes and insects flying and crawling about but I didn't get one single bite. I've tried other drugstore type products and have always gotten bitten. I like the compactness of the tube which was nice since it was easy to put into my fanny pack during my hike and other activities. I also purchase the REI 100% juice and applied a small amount of it on top of this product to be double sure to protect me. It worked!! I shared both products with my friends and no one got bit! :o) The only reason I didn't give this a 5* was the price.
After trying every form of insect repellent in four different stores, I have settled on Ultrathon. It has protected me from black clouds of mosquitoes while kayaking in Alaska, and also prevented ticks on the Appalachian Trail. I can get by with only applying once a day (and I sweat a lot) and the chemicals never seem to bather me. I prefer the cream to the sponge applicator since I feel that it allows my to have a more effective coating, but that's just my preference. It is expensive, but if you are tired of being eaten alive it's perfect. Try it once and you'll never regret it.
Perfect insect shield in the Amazon!
I applied the 3M Ultrathon Insect Repellent first thing in the morning and it lasted all day. Not a single bug hovered around me. One tried landing on me, but immediately flew away. It only requires a little dab (about the size of a pea) to cover the entire face. Our tour guide recommended applying with the back of the hand, so the DEET wouldn't transfer to any plastics (camera, etc) and melt. I didn't find the smell objectionable at all, strangely it smelled a little like 3M tape. I only got bug bites after I showered for the night, removing the insect repellent.
Boundary Waters Tested, and Approved.
I love this stuff. The mosquitos in the Boundary Waters can be pretty bad and I put this stuff to the test. I'm not sure how, but it beat the deet.
One particularly nasty night, I had someone else apply Ultrathon on the back of one of my hands, and sprayed "100%" deet on the other hand. I held up both my hands in the firelight and watched as Mosquitos did "fly-by's" on the Ultrathon hand, where some Mosquitos would land directly in the fresh deet on my other hand. Amazing stuff, I wont use anything else.
My wife and I went on our honeymoon in Mexico, which included a horseback ride through the jungle. We put this stuff on our exposed skin before heading out along with our sunblock. Within 30 minutes, we were sweating so much that we could see the sunblock bead up on our arms. There were also mosquitoes everywhere. We looked at the people in our group and all had huge stings over their entire bodies, while we were not bitten once.
This is some serious stuff.
I haven't really had any experience with any other DEET product, but I can say that this thing works and works well.
On one backpacking trip, a particularly gargantuan and aggressive swarm of mosquitoes decided it was going to demolish my group and I. Fortunately, I just applied this stuff and they disappeared save for some outliers. I did have to apply it to my clothing (which isn't ideal), but these guys were biting my shoulders through my shirt.
This product works very well.