It's not a cure-all Loubylou but do give it time
. There is a myriad of reasons why your skin, teeth and nails are not in great condition. Eating a good varied balanced diet with lots of fresh ingredients including copious amounts of fruit and veg, as well cutting down on carbs, unnecessary fats and fatty foods, and sugars - will do you the world of good as some vitamin and mineral deficiences can cause skin and hair problems. Fresh air, plenty of exercise including weight-bearing and body conditioning, drink lots of water, no smoking, limiting alcohol, getting enough sleep - are also crucial! However you cannot reverse the ageing process although you can work hard to do the best you can for yourself and your skin/hair!
If you've done all that and taking HRT and still having skin problems - then a visit to the doc would be in order to rule out other conditions - for example underactive thyroid can cause these symptoms, but in this case you would also be feeling unusually cold and also have weight problems not due to diet and lack of exercise.
Hurdity x