monophasic birth control

[tiredpoet]

Hi!  Could you help me with a question on birth control pills?  I was on a triphasic pill for years (Tri Sprintec).  It was good for keeping acne under control (which is why I originally went on it at age 20).  But in the last few years I began suffering from extreme fatigue, lots of water retention, vaginal dryness, etc, and as all my tests were normal my PCP suggested the pill was causing it.
I went off the pill completely 4 months ago and about 2 months after started experiencing extremely oily skin and massive hair shedding, among other things.  It seems I can't keep my skin under control without being on the pill, so I saw my gyn and she suggested I might feel better if I have a steady dose of hormones instead of the varying levels Tri Sprintec provided.  She prescribed Sprintec, which I will be starting next week.
Could you help me understand the difference of how these two similar pills work?  I know they are the same hormones, but how much do the levels differ?  It seems as though the Sprintec contains the same level of hormones as are in the third week the Tri Sprintec - is this correct?  
Also, I keep reading that it's the norgestimate that helps with acne due to it's low androgenic activity.  Do the hormones in the pill "replace" my body's natural hormones, or how do they affect me?  
Thanks in advance for any help you can provide!

[tiredpoet]

Thanks for your reply!!

[Sandra Y, RPh]

Here is the comparison between Sprintec vs. Tri-Sprintec.  Yes, Sprintec contains the same level of hormones as in the third week of the Tri Sprintec (Day 15-21). Sprintec has the same amount of hormones for the 3 weeks of active pills, while the Tri-Sprintec increases in norgestimate each week.

Sprintec®:
Day 1-21: Ethinyl estradiol 0.035 mg and norgestimate 0.25 mg (28s) [21 blue tablets]
Day 22-28: 7 white inactive tablets (28s)

Tri-Sprintec®:
Day 1-7: Ethinyl estradiol 0.035 mg and norgestimate 0.18 mg [7 gray tablets]
Day 8-14: Ethinyl estradiol 0.035 mg and norgestimate 0.215 mg [7 light blue tablets]
Day 15-21: Ethinyl estradiol 0.035 mg and norgestimate 0.25 mg [7 blue tablets]
Day 22-28: 7 white inactive tablets (28s)

Norgestimate is a synthetic form of progesterone, which is important for the regulation of ovulation and menstruation. Norgestimate does not replace your body's hormones, but helps to maintain hormonal balance. Acne commonly occurs when there's a hormonal imbalance. By having a consistent levels levels, it may prevent acne formation.