First-aid, and the contents of one’s first-aid kit is a surprisingly contentious topic among backpackers. I’ve heard ultralight backpackers proudly state that their only first aid items are a few bandaids and a couple of alcohol swabs. I’ve heard the same UL backpackers suggest that if they need anything else, “I can probably borrow it from someone else”. Now there’s nothing wrong with spreading the weight around when you’re in a group, but if you are relying other people to unknowingly carry the things you might need, I’m not sure you can properly call that “ultralight”. “Explotative”, maybe. My feeling is that you can either be the sort of backpacker who’s always borrowing things (first aid items, repair tools, food, spare clothes, etc.) from others on the trail, or you can be the sort of backpacker who’s always loaning those things out. And I’d prefer to be the latter.
My first aid kit weighs 12oz and contains
Caffeine pills (8)
Cortizone cream pouches (5)
Naproxen (Aleve, 8)
Nitrile gloves (1 pair)
Pepto Bismal tablets (8)
Vetrap (athletic tape, 5yds)
I have 8 of every pill, all in individual bags, labeled with contents, dosage, and how many to take. Many things have more than one use: maxipads and tampons aren’t just for giving to any female hikers in need; both are for “heavy flow” and thus can be used for puncture wounds, nose bleeds, etc. A ziplock bag can be taped over a sucking chest wound. Safety pins and rubber bands are, of course, infinitely useful. But it’s worth noting that I have first-aid training; the general rule is that you shouldn’t take anything you don’t know how to use. (Tho’ I personally think of that as a suggestion to get more first aid training, rather than to carry less stuff! But then again, another first aid maxim is that it’s better to carry 10 lbs of knowledge than 10 lbs of supplies…)
Some notes on specific things:
For antibiotic ointment, bear in mind that some people are allergic to the “triple antibiotic” kind.
In a similar vein, some people are allergic to latex, hence the nitrile gloves.
Some items that can be used for first aid are stored in other parts of my pack. For example, a syringe is useful for irrigating wounds; I have a large one as part of my water filtration system.
Although you can never plan for every contingency, my own opinion is that it’s irresponsible to not take basic precautions. Am I interested in saving weight? sure, but just as I wouldn’t go out without sufficient water (on the theory that I’ll either find some, or bum some off another hiker, or maybe just not get thirsty) I wouldn’t want to go out without a basic set of first aid tools.
I should mention that my daypack has a few first aid items that are either too bulky or too heavy for backpacking, most notably, a pair of Ace bandages. I may throw in a lightweight knee brace, too. My backpacking first aid kit fits into a 3x3x6 inch zippered pouch; there wasn’t any room left for bulky items like rolled bandages.