I'm a physician so I have my take on issues. The medical community think most supplements are ineffective and the reason for that is there are no randomized double blind independent research studies conducted over a decent sample size over several years. I have yet to see one of these studies published in the Journal of the American Medical Association or New England Journal of Medicine which are arguably the two most prestigious and difficult journals to get published in. The FDA has no jurisdiction on the herbal/supplement industry so anyone can make false claims. If I was greedy, I could market some product, say I was a physician and sell it in health food stores and people would probably buy it. There is a lot of junk out there and it's sad the FDA doesn't regulate it.
Also be skeptical of certain research studies. Most of the time, the company that puts out the product sponsors their own research so do you really think they are going to find something negative with their own product and if they do, do you think they will publish it?
If anything, supplements could hurt you because you don't know what is in it and there are many products that are carcinogenic or may be carcinogenic. You could also have anaphylaxis to certain products that you may be allergic to. For example, in the early 90's, they used to sell ephedera as a weight loss supplement or a "cutting" formula. Ephedera's base structure is similar to many amphetamines and later was known to cause congestive heart failure and tachycardia. That's but one example!
The truth is your genetics plays a bigger role in strength and power than you might think. For example, you can't increase the number of muscle fibers that you have; you are born with a set number, but you can enlarge the ones you have. That's why some of your friends are just naturally strong although the never work out. Honestly, the only real way to guarantee results is to use steroids or human growth hormone which I don't recommend for a variety of reasons. Creatine has been found to negatively impact the kidneys and thus I don't recommend you take it.
Plus, ask yourself why you want to gain weight. I played football in high school and I was like you. I was thin but strong. I wanted to gain weight for looks. There are advantages to being strong and lean. Adding extra weight could slow your 40 time and hurt your agility. Yes, with added muscle, you willl increase power but you will also increase your weight. In addition, drinking weight gainer and powders like that will not add pure lean muscle. Those powders are loaded with carbohydrates and sugar which will just add fat.
Also, a lot of the information published in Muscle and Fitness etc. is junk science written by trainers and sometimes PhD's who perform biased experiments on a small population who is trying to get published. Any publication can find a "study" to support it's claim, the difference is that most "study" are not randomized double blind studies performed on a large sample size over several years. Double blind means both the experimenter and the subject are unknown to each other (the doc doesn't know which group is the control or the experimental group and the subjects don't know which is the sugar pill and which is the drug) Randomized means the subjects were chosen at random and not selected by the researcher to accomplish a known result or a potentially known result (bias).
Finally, many physicians are greedy and are paid to testify to a certain supplement because they are paid thousands of dollars to do. We get phone calls like that all the time and most doctors refuse to ruin their reputation or put their patients at risk by endorsing a supplement. We all laugh when we see some doctor announce how he or she recommends a supplement.
