Diet, exercise and stress reduction are important even if using hormone therapy. They should be the first alternatives to consider and will be discussed under old age below. There are some alternative non-hormonal medicines which may help some with symptoms. For hot flashes there is Clonidine which is an antihypertensive drug in the form of a patch or pill and Bellergal which is a combination of belladonna and ergotamine with Phenobarbital. Bellergal is FDA approved for the treatment of hot flashes.
Some women find help from many different substances.
None of these is well known or predictable in action and use of any herb or other supplement is a personal experiment. It would be wise to only add one thing at a time and to be wary of unwanted side effects so it can be stopped at once if there is a problem. Better still, if you want to try herbal therapy, would be to consult with an herbalist, homeopath, Chinese medicine doctor or naturopath. Don't forget to tell your regular doctor that you are taking herbs because they are medicines and can interact with other prescribed medicines or have side effects. Phytoestrogens as in soy products are very popular these days.