Botox has been around for ages and is considered to be a very safe and well tested product. Yes, some people may have adverse effects, but that is true with anything. The only way to weigh up the pros and cons for you, is to make an appointment with a dermatologist and discuss it. Once the actual risks as they pertain to you have been set out, then you can decide whether it is worth it or not.
I think that a good and long term relationship with a good and sensible dermatologist is key to not looking like a complete tit as the years go by. Trying to freeze your age at, e.g. 35 is going to look increasingly daft as the years go by. Better to aim to look a few years younger, or a bit more rested - goals that take into account your overall ageing process and how your skin changes. A good dermatologist should be able to guide you.
I think of it like getting your highlights done - you start off with honey blonde and it looks fab, but then this becomes the new normal and you stop noticing what's actually been done, and it's tempting to go blonder and blonder. A good colourist will rein you in.
You don't automatically end up with parts of your face frozen. It's a paralysing agent, so if you inject less, you will end up with partial paralysis and, therefore, still some movement. My dermatologist offers a free 2-week top up - that way you can inject less initially and if you find you want a bit more, then you can go back. Easier to get a more subtle result that way.
I'd say go for it, but choose where you go wisely. If you want recommendations there are loads of people here from all over the country who can help. If you don't like it, it'll wear off and you don't need to do it again.
