Tingling Sensation from Liquid Rogaine

My question involves Rogaine Liquid 5% and Rogaine 5% foam. I switched to the foam (after about 3 months on the liquid) about two weeks ago and have noticed that the tingling sensation has ceased. I used to feel the tingling on and off throughout the day. I began using the liquid with a shaved head (it is now grown out to about 1 inch) and it is difficult to gauge any increase in shedding but from 3 weeks ago to now, it seems like there is an increase.

My questions are :

1. Is there an increase in shedding when starting the Foam after having used the liquid?
2. Is there evidence that the “tingling” sensation is correlated to absorption into the scalp?
3. If application/time is not a big issue, which of the 2 do you recommend?

There’s no difference that I’m aware of between any initial shedding from the foam or liquid. Tingling may have a correlation to absorption, but the foam does provide better absorption than the liquid. The tingling might just be from the amount you’re applying, or perhaps you have a sensitivity to a secondary ingredient in the liquid that isn’t in the foam.