Gary,
I have been on this for over 30 years and have had the dosage adjusted up or down several times. It is very important to have regular blood work because the dosage must be varied precisely with the need and a slight change can have a big efect. When I was first on it I had problems because I did not go for the blood work. Once the dosage was cut, I was OK. It may require several weeks or even a few months for the thyroid function to level out. I can sometimes tell by a cluster of changes that I need a different dosage.
As Brian says, the side effects listed could be symptoms of various other situations and may be only temporary. Many of these are meerly an indication of a need for adjusting dosage and are only uncomfortable situations. "Notify your doctor promptly" because you may need to have the dosage changed.
You are probably in more likely to sustain a serious injury in your own kitchen or bathroom than you are to suffer from the possible side effects of thyroid medication. If you go back and read the list you will see that the more serious effects are ones for which you would seek immediate help anyway.

Malka