First and foremost, I would recommend talking to your doctor before you start any over-the-counter supplements, as there are side effects and possible interactions.
If I were to recommend any supplement, I would first recommend black cohosh. Side effects CAN include weight gain, headache, rash....(again, I want to emphasize *can, as this does not mean you will experience these side effects). While more rare, but serious, people taking black cohosh have had liver toxicity. You should be able to buy this at a drug store (I've seen it as Remifemin), and you can take one 20mg tablet in the morning and one 20mg tablet in the evening. If you would rather not take tablets, I believe black cohosh tea is also available.
Again, I would HIGHLY recommend talking to a doctor before starting, but that's what I would recommend! Good luck.