What causes permanent lactation?

[Ranma]

So i just started a new game got milky and went to Poe A and got the helmet and now the game says im permanently milky, i dont mind since i was going to do it anyway later on, but now im wondering what exactly causes permanent lactation.
I assumed it was just mixing Milky with another milk based perk but i guess i was wrong.

 

[KAZEARC]

if you use lactaid overdrive you can get the hypermilky perk.

 

[Theron]

1. Hypermilky (5 Lactaid Overdrive in 24 hours or DracoGuard while pregnant)
2. Mega Milk ('Milk Self' at Ellie)
3. Honeypot (Gold or Orange Pill, must be lactating)
4. Milk Fountain (Treatement: Cum-Cow)
5. Milky + Treated Milk
6. Vanae Milk type
7. Bounty Bra (New Texas Gift Shop)