Probably amphetamines, people love to shit on amphetamines when it comes to their use in treatment of ADHD. Most of that criticism comes from a fundamental misunderstanding of both chemistry and biology.

Since no one else mentioned it. Stress, stress can lead to both of these things. Premature greying and hair loss. Thankfully the hair loss is usually temporary if it is caused by stress, although the greying is not.

So if you lead a pretty stressful life. Find some ways to relax and try to get enough sleep.

I started losing hair in clumps in my mid to late 20's. Then had a major life event that was the peak of that stressful point in my life and now a little over a year later most of my hair has grown back. The grey is all still there, but my hair grew back.

Genetics are often the cause of hair loss, but don't discount stress.

Keep up the good work! Remember that sleep is just as important as nutrition when it comes to recovery and building strength.

Honestly that's probably one of the best things you can do as you enter your middle ages. Get strong, stay strong, but don't push yourself as to cause injury or degrade cartilage and connecting tissues.

What is your training frequency? And do you have any other goals outside of 350lbs for your deadlift?