Let's see...
You: Hey Pal!
Him: Hey! What's up, buddy?
You: Nothing much, dude. I think I'm getting obsessed with science. Science can explain almost everything, man. I've reading about hairs for about three months now, and trust me, I couldn't ever have anticipated that the science of hair is so deep.
Him: Why are you so interested in hairs? There are so many things about science that could fascinate you, aren't they?
You: Well, I actually wanted to try a new crazy hairstyle, but my hairs aren't enough for that. So, I thought that maybe science could help me with the problem of my hair loss. This form of hair loss is called Androgenic Alopecia. It affects most of the males and is sometimes so aggressive that it can make you slick bald at a very young age.
Him: So... Did you get any help?
You: Yup. I found out the cause and now I'm tackling the loss with a purely scientific method, instead of believing any anecdotal or non-anecdotal claims. And trust me, it's working. I'm so happy now. By the way, do you mind asking something about you?
Him: Nah, be free to ask anything buddy.
You: Aren't you worried about your hair loss? You are currently on third stage of Hamilton-Norwood scale, whereas I'm just on the second, and the very thought of going bald petrifies me. How do you manage to stay so cool about your hair loss?
Him: Well, to be honest, even I don't want to go bald. But what could be done for this? Baldness is inevitable and everyone had to learn to deal with it and accept it as soon as possible. I'm looking forward to see some good results from the natural remedies like the snake oil, but if it doesn't have a beneficial result, I'll leave it. What do you think about it? And how are you curbing your hair loss?
You: Well, I know that it's an earth-shattering news for you, but trust me, natural remedies don't work. It's not something that I think. Science proves it. But science has cure for Androgenic Alopecia. Because it knows the root cause of it.
Him: And what's the cause?
You: You know what testosterone is, right? There's an enzyme in our skin called 5-alpha reductase enzyme type-2, that converts our lovely testosterone to an evil hormone metabolite called DHT. This DHT is the culprit.
Him: But I heard that it's genetic.
You: The hair loss is not genetic. The androgen sensitivity of the scalp is genetic and this is what makes a few of us susceptible to Androgenic Alopecia.
Him: Hmm... And how're we supposed to cure it?
You: There are certain compounds that are enemies of this creepy enzyme. If we kill the enzyme, tissue DHT in our scalp won't be formed and hair loss will stop, provided it is Androgenic Alopecia...
(Explain everything to him from IGF-1 to nocebo effect of minoxidil.)
This should must probably work. You may as well ask him to join this forum. Show to him some statistical information about the research data collected from the clinical trials of these medications. There are a few sites, like Wikipedia, that provide a detailed analysis about most of the medicines.
If you need any more suggestions, just let us know. Hair loss is a very sensitive topic and you need to sound very very empathetic to him, to make sure that your words don't harm his self esteem and confidence.