How much time does it take for an MVP to kick in?

Hey all,

Greetings from my side. I am a Founding member of my organisation which is in Healthcare domain (First time being given this opportunity). I am by definition an engineer, but slowly stepping into the role of a Product Manager as well.

We have been building our product since May, and seems like the MVP is now shaping up. I would like to understand how much time does it take for an MVP to be proven right or wrong? A usual average time from scratch to the getting out of stealth.

I understand it's a vague question, but I would like to understand other people's perspectives and their expertiese.