SpaceShipTwo can accelerate as much as 3.8 g during accent and up to 6 g during reentry. I don't think they will be sending him up if there is even the slightest risk to his health.

Reference: http://www.parabolicarc.com/2009/12/07/spaceshiptwo-whiteknighttwo-specs-flight-profile/

Four cosmonauts have stayed for 365 days or longer continuously in space during the 1990's. The record for the longest space flight being held by Valeri Polyakov who stayed on the Mir space station from 1994 - 1995. Russian achievements are often obscured because of the uncomparable public involvment by NASA.
See: Ten Longest Space Flights

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Wanda Says:
We used to look up at the sky and wonder at our place in the stars. Now we just look down, and worry about our place in the dirt.
    -- Copper, Interstellar (Movie) (2014)