Sodium fluoride is one of the most common active ingredients in toothpastes worldwide. Its effectiveness in strengthening enamel is confirmed by dental practice, and at the concentrations typical of consumer toothpastes it is considered safe when used correctly.
The main rule: spit the toothpaste out after brushing rather than swallowing it. This is a standard requirement for all fluoride toothpastes for adults. After brushing, simply spit out what is left; there is no need to rinse your mouth with water straight away, and some recommendations even advise against it so that the fluoride stays on the enamel longer. But this is a matter of personal preference and habit.
If you take fluoride supplements prescribed by a doctor or live in a region with a high fluoride content in the water, check your total daily dose with a dentist; this applies to any fluoride toothpaste, not just this one.