Without trying to confuse you with complex information that exceeds almost everyone’s knowledge base (including mine), I can reiterate some of the more common findings.

First, know that the liver is the only organ in the human body that is capable of regeneration. The workload that this organ bears pretty much demands it.

Now there are different dietary supplements that have been proven in different clinical trials to cause damage to the liver and other organs. There are several theories as to why, one of the most accepted (and I believe it to be true) is that supplement manufacturers are not regulated by the FDA, which means they can pretty much do whatever they want, even without scientific backing. This is because of the "dietary supplement" classification. The theory is that most of these companies have no idea what the true effects of their product will have because they are combining substances that have never before been attempted, and with no legitimate studies or trials to test for safety or effectiveness.

As far as amino acids go, there is no substantial or undisputed proof that an excess of protein in the diet (including amino acids/BCAAs) causes damage to the liver. This has actually been one of the more common studies since the majority of north americans have a high-protein dietary lifestyle.

The fact is the body cannot store protein. It only takes what it needs at the time. Any excess or leftover amino acids in the system are converted by the liver to other usable substances. It’s called deamination, and the process goes like this:

-converts nitrogen from the amino acid into ammonia
-ammonia converted by the liver into urea (urea cycle)
-urea excretion is performed by the kidneys

These organs can effectively handle the extra workload, as long as the organs are healthy. If there is any type of pre-existing kidney disease, however, then you may have problems (and possibly serious ones). This is when a doctor will usually prescribe a reduction in protein intake. Other than that, amino acid supplements, taken in moderation, will not damage the liver or kidneys.

My suggestion to you is to do your research. Know every ingredient that is in the supplement you want to take and talk to a doctor or a Registered Dietitian (RD). Anyone can call themselves a nutritionist, there is no formal educational training for such a title, so make sure the person is an RD. You actually have to obtain a bachelor’s degree and pass a national certification test (an extremely long and difficult one) to become an RD.

My last piece of advice is to make sure that whichever supplement(s) you do take, do not overuse them. Don’t take too much at once and make sure you are cycling off the product. Remember, your body adapts to everything you do, which is why cycling supplements is crucial.
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It’s possible it can do liver damage if you use it over a VERY long period of time, but you haven’t specified how long you are planning on using them.
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