If you would like to try something natural and safer first, try Creatine powder.
It is used in huge doses by body builders, and can also be used at much smaller doses to help old people to be able to open jars, get up out of chairs by themselves, etc.
I figured that I feel like I am very old, so I tried it. It was a miracle. I was able to start doing a weight lifting routine without pain within a week, using many reps with small weights, so as not to rip my tight muscles from Fibro. I can now carry a full watering can in the garden. I never could have it more than 1/3 full before.
I've been told those who eat a lot of meat will not get much benefit, but I am mostly lacto-vegetarian and only eat a little meat. Still, I think it is worth trying, even if you eat a lot of meat, since a huge jar only costs about $25.
Dr. William Douglass has written a lot about using creatine to increase muscle strength in those who can't exercise so they can remain more independent in their old age. He is quite a maverick and hates to exercise. He says creatine is just as good. I don't know about that, but it sure helped me to be able to exericse more and handle more daily duties without resting.
I take 5 grams, 3 X week, before working out. That seems to be enough for me.