I went on the one month immunisation programme at the Somatheeram Ayurvedic Health Resort (not to be confused with the very similar sounding hotel resort next door). As a result, a problem with my hip has been completely sorted, I lost five kilos (and wasn't even on the slimming programme) and feel very balanced and much more informed about diet, exercise and the philiosophy and understanding behind Ayurveda. I particularly enjoyed the pranayama (breathing) yoga at dawn every day, relaxing in the swimming pool with fresh coconut juice, more traditional yoga for an hour and a half before lunch, daily consultations with the doctor and an hour and a half treatment every day. The food was delicious and we were given lots of advice on the right combinations for us.
Don't expect the massages to be as in the west. They range from full body massages with a lot of herbal oil, to herbal 'baths' to being pounded with pouches, to oil baths, to the rice pudding treatment or 'cleopatra' baths with milk. Then there is the purgation day (or night) and possibly some enemas. I.e. expect treatments rather than always relaxing massages!
The weight disappeared automatically with the lifestyle there. Actually I wouldn't recommend the slimming diet quite so much as sometimes it looked a little uninteresting compared with the range of foods I was eating. Everyone was able to lose weight during the month whatever programme they were on.
I was there in Feb/March and it became very very hot in March, so I wished I'd chosen a 'special cottage' with air con. Fans didn't always reduce the heat enough. However, the standard cottages are fine and would be at the less hot times of the year.
Bring some extra money with you for tips. I'd say about £50 for a two week stay, as these are very much appreciated by the staff.
And if you like shopping, then you're in for a treat in terms of clothes, pictures, jewellery etc. There's lots in Trivandrum although we particularly liked FabIndia - more expensive than most places but top quality crafted goods.
We enjoyed the backwaters trip and also one to the Neyyar Dam, but try to get to the latter before 9 when the elephants are being washed. And check in case you want to book a boat ride to see the lions (yes lions!) - as this may need to be booked the day before.
All in all, a great break and highly recommended. And did I say how friendly and helpful the staff were, from the receptionists, to the restaurant, to the yoga teachers, cleaners, gardeners, and lifeguards? Highly recommended, although we might come at a slightly cooler time next time.