I don’t get anything out of cold medications. By the time my symptoms are severe enough that I take something, it’s already too late. The only thing that has ever works for me is rest and giving it time.
You may be luckier. If you have a stuffy nose, you could try pseudoephedrine, the active ingredient of Sudafed and Claritin-D. At the drugstore, next to pseudoephedrine, you’ll also find phenylephrine nasal spray. Even though it’s next to pseudoephedrine on the shelf and marketed the same way, phenylephrine isn’t going to do anything for you. Given its lack of effectiveness it’s strange that it’s available at all, although that may change.
What’s even stranger is that there are other active ingredients that have inferior alternatives, yet the inferior product is equally or more commonly available.
Consider water purification in the backcountry. In case my water filter clogs up, I also carry chlorine dioxide, which kills viruses, bacteria and protozoa. It’s not the most easily available water treatment, and it takes a few hours until water becomes potable, but that’s okay for a backup system. On the other hand, more commonly available treatments like iodine or sodium dichlorisocyanurate don’t kill protozoa like Cryptosporidium, which is a serious drawback.
Insect repellent is another example. DEET is the most commonly available active ingredient, but it smells bad, feels greasy when applied to the skin, and causes damage to synthetic fabrics. On the other hand, icaridin (also known as picaridin) will not damage gear, has less of an odor an feels okay on the skin. It’s also as effective as DEET. Yet insect repellents with icaridin are harder to find than DEET-based ones.
You’d assume that the market would make sure that unless there’s a big price difference, the most effective treatment is the one that’s most easily available, but clearly that’s not always the case. My guess is that the reason is that information about efficacy isn’t that easy to come by.
Nehaveigur 