I just looked it up on www.drugs.com. I can't see anything on there about it stopping periods permanently. Wouldn't the contraceptive pill or injection be more along the lines of what you need if that's your goal? Maybe the GP wasn't focusing on the exacerbated neurological symptoms?
This is the main bit from the drugs.com site:
1. Metropathia haemorrhagica (dysfunctional uterine bleeding): 5mg three times daily for ten days. Bleeding is arrested usually within one to three days. A withdrawal bleeding resembling normal menstruation occurs within two to four days after discontinuing treatment.
Prophylaxis of recurrence of dysfunctional bleeding: if there are no signs of resumption of normal ovarian function (no rise of morning temperature in the second half of the cycle), recurrence must be anticipated. Cyclical bleeding can be established with 5mg twice daily from the 19th to the 26th day of the cycle.
2. Pre-menstrual syndrome (including pre-menstrual mastalgia): Pre-menstrual symptoms such as headache, migraine, breast discomfort, water retention, tachycardia and psychic disturbances may be relieved by the administration of 10 – 15mg daily from the 19th to the 26th day of the cycle. Treatment should be repeated for several cycles. When treatment is stopped, the patient may remain symptom free for a number of months.
3. Postponement of menstruation: In cases of too frequent menstrual bleeding, and in special circumstances (e.g. operations, travel, sports) 5mg three times daily, starting three days before the expected onset of menstruation. A normal period should occur two to three days after the patient has stopped taking tablets.
4. Dysmenorrhoea: Functional or primary dysmenorrhoea is almost invariably relieved by the suppression of ovulation. 5mg three times daily for 20 days, starting on the fifth day of the cycle (the first day of menstruation counting as day one). Treatment should be maintained for three to four cycles followed by treatment-free cycles. A further course of therapy may be employed if symptoms return.
5. Endometriosis (pseudo-pregnancy therapy): long-term treatment is commenced on the fifth day of the cycle with 10mg daily for the first few weeks. In the event of spotting, the dosage is increased to 20mg and, if necessary, 25mg daily.
After bleeding has ceased, the initial dose is usually sufficient. Duration of treatment: four to six months continuously, or longer if necessary.
6. Menorrhagia (hypermenorrhoea): 5mg two to three times a day from the 19th to the 26th day of the cycle (counting the first day of menstruation as day one).