Pregnenolone is a steroid hormone produced from cholesterol in the adrenal glands. The best way to think of this hormone is that it is the first off the conveyor belt. Without its presence our bodies cannot properly produce DHEA, progesterone, estrogens, testosterone, and hydrocortisone. Pregnenolone, which is also produced in the brain, also affects many neurotransmitters.
Like all other hormones, this declines with age. Many doctors use pregnenolone to treat memory problems, depression, fatigue, and can be helpful with autoimmune conditions.  I guess that’s why so many middle age people get diagnosed with depression, moodiness, forgetfulness and arthritis!!!  Ugh!
As with all hormones, clinical doses go a long way in our ability to function and be well.  At 50, we shouldn’t be producing anything near what we did at 20 of ANY hormone. A dose of 10 to 25 mg. per day of pregnenolone is all that is necessary.  For more information on adrenal gland function, see my previous articles.