I'm no expert, but I looked into this issue for my mom some years ago (had cancer on her liver) and what you're looking for specifically is Silymarin, the ingredient in Milk Thistle that actually has the protective benefits.
The issue with raw Milk Thistle supplements is that it's a lower dose of Silymarin as you're just getting the plant, you'd want "Milk Thistle Extract", which is concentrated Silymarin. As with all supplements though, read the label and research the brands you buy. Counterfeit products are rampant in the industry, as is inconsistent dosing.
I'm not sure if there's been much of a more recent update to this in the past 8 or so years, but my recollection of Milk Thistle studies is that they're largely ineffective for liver disease and marginally effective for acute hepatitis.
Also research NAC [0] supplements. They work as a precursor to glutathione in the liver which is typically depleted during the course of alcohol consumption. Might only be effective for acute effects of alcohol though.
Edit: Also, make sure your friend is consuming coffee [1].
Liver disease (chronic)
Several studies of milk thistle in liver disease caused by viruses or alcohol report improvements in liver tests. However, most studies have been small and poorly designed. More research is needed before a conclusion can be made.
I have taken milk thistle. Some people don't tolerate it well. There are alternate things that can be taken in that case.
Looking back on my notes, the reason it helps is that it boosts glutathione. IIRC, you cannot take glutathione directly as a supplement. So, instead, you need to take things that help the body create glutathione, and milk thistle is one of the things that can do this.
If you don't tolerate milk thistle well, you should research glutathione precursors. But be aware that a lot of the websites you will most readily find are kind of sketchy.
You also need to remove the stress from the liver. Said friend needs to stop drinking. It may also help to do other things to reduce stress on the liver.
I've been taking it for a while - hasn't had any noticeable benefits for me, but based on my research online and asking a few doctors there is no harm in taking it. No downside, possible upside so go for it.
