I was put on Duac at the beginning of the year and it was a marvellous revelation, finally after 25 years I had clear skin. I totally loved its drying effects. However, my GP told me that I couldn't keep using it because it was an antibiotic and gave me Differin to try. I've had it for nearly 3 months and it is nowhere near as good. I have been told to persevere for 3 months to give it a full try but I'm hating it. So the alternative would be....
Pretty much anything which is properly effective for cystic / severe acne will have unpleasant side effects.
Antibiotics strip your body of good bacteria and can cause digestive probs, candida overgrowth, resistance and all sorts of other problems, and are incredibly over-prescribed so much so it's seriously worrying.
Roaccutane has liver risks yes, and is teratogenic but if carefully monitored and no chance of pregnancy I'd say it's a good bet for the chance of a cure. Does cause peeling of skin and sun reactions too I believe. Derm will prescribe.
Anti-Androgens are good for some people (totally worked on me) , however are also teratogenic to the male fetus and some studies have suggested a link with Spiro and cancer (lab rats given Spiro showed a higher incidence of tumours, however they were given a HUGE dosage to body weight compared to humans). Spiro is actually a heart failure / blood pressure medication but has the side effect of reducing androgens. For effective treatment you need 100mg - 400mg a day, which is a high dose and will almost certainly cause symptoms such as constant visits to the loo, dizziness etc. I take 100mg only because I am quite small with low blood pressure as it is and I certainly feel the diuretic effects and have to follow a low potassium diet. An Endocrinologist or PCOS specialist (repro medicine) will prescribe this, but a GP will look at you as if you are crazy if you request it (been there done that ). The pill Yasmin has an ingredient which is an analogue of Spiro (equiv to about 25-50 mg Spiro a day) , that's why it is known for no bloating , no weight gain etc.
I also take Gedarel 20/150 (Mercilon) pill which seems to help too. Marvelon it's big sister pill in terms of oestrogen helped better but I had oestrogen withdrawal syptoms in the break week which were hellish even if tricycled the packs. But different pills suit different people. Popular acne pills are Dianette (I decided to try the safer pills first), Yasmin (my PCT won't prescribe as too expensive), Marvelon, Cilest. Worst theoretically are the mini pills (Cerazette in particular), Microgynon, Brevinor. But again, everyone is different.
The herbal remedies Agnus Castus and Black Cohosh are very very good for regulating hormones (Agnus Castus if you have too frequent periods or for conception, Black Cohosh if too few periods and menopause) but not good to take along with the pill as they work against it's action (ie they promote fertility rather than suppress it)