Is it true that the benefits of most drugs produced by pharmaceutical companies have not been proven?

No, not true! The use of drugs with unproven efficacy is prohibited. The question is different if some pharmaceutical company falsifies the facts and results of preclinical and clinical studies. Just read how the clinical trials of drugs are carried out https://crlabcro.com/provedenie-klinicheskih-issledovanij and it becomes clear that without a number of stringent requirements, the drug will simply not be allowed for registration and released into circulation. Another question is that different countries have different views on pharmacology, but the scheme of proof of effectiveness is accepted by the international community and enshrined in the declaration of good clinical practice

Yes, it's true, for many there is not enough research, or there is, but these are studies of the ̶ / ̶b̶ / ̶ D level. And there are also Generics and just tablets with a small amount of active ingredient, such drugs seem to be the same as the original medicine, but are ineffective. Although this is not always the case. It happens that paracetamol is sold under the guise of Teraflu, for example, it seems to work, but in fact the buyer overpays for the brand and extra supplements. Or else dietary supplements and weed in tablets, but with some loud name "Hepoprotector Carsil Forte +".

There is a good site that will help you better navigate this and save money http://encyclopatia.ru/wiki/Running_list of_preparations. Or you can just focus on the drugs used in the USA.

Do not listen to arguments that have already been written to you in response. Specifically, this is very important in Russia. There is such a thing as Evidence-Based Medicine, and in the USA, European countries, the principles of doc. medicine is actively used and it is allowed to treat people only with those medicines that have proven their effectiveness. Evidence means that they have successfully completed a randomized, double-blind, placebo-controlled trial. This, in turn, means that the sample of patients is randomized, neither the patient nor the doctor who supervises the study knows who is given a placebo and who is given a drug (the principle of double blindness), and the results are generally evaluated by another person, well, placebo-controlled is understandable. What means. So, if at the end of the study the results indicate that the drug is more effective than placebo, this case is registered and the drug is allowed on the market, it is added to various recommendations, then studies are carried out to compare the new drug and older ones from the same area, suddenly a new one the drug cures better than placebo, but worse than older drugs in the same group.
In order to understand which drugs are effective and this has been proven, you can focus on sites that every self-respecting doctor should not pass by.

www.fda.gov Food and Drugs Administration, this is the place to find out if a particular drug is registered or rejected for use in the United States

www.cochranelibrary.com - Cochrane Research Library and reviews of what it is, you can read here in Russian -russia.cochrane.org

www.nhs.uk - Analogue of the FDA, only European.

Speaking of Russia, we do not require specific research to bring a drug to the market, if you look at it, here are drugs that you will not find in the list of approved sites on the above-described sites: Actovegin, nootropics, hepatoprotectors, absolutely all homeopathy (for this is generally a real heresy), most of the antiviral drugs like Ingavirin, Arbidol, and so on, in Russia it all just goes to waste. By no means can we say that we have all the counters filled with such dummies, but still, there are quite a few of them.