IV therapy is generally very safe. There can be minor trauma at the insertion site of the IV resulting in bruising or temporary swelling. If you experience any discomfort, let you nurse know.
On the thumb side of the wrist runs a superficial nerve called the radial nerve. This nerve can be injured when IVs are started in this area. If at all possible, avoid having IVs placed here.
A condition called phlebitis, or inflammation to the walls of the vein, can happen with stronger IV infusions such as high dose Vitamin C, NAD, and some other nutrients. If you notice any irritation to your vein after your treatment, let your nurse know. A highly effective treatment for this is castor oil compresses and heat to the area.
Although extremely rare, some people can have allergic reactions to some of the ingredients in the drips. For example, those with sulfa allergies may react to glutathione. High dose vitamin C treatments requires checking a G6PD level, an enzyme deficency in some individuals.
Vitamin D should only be given when there is a known deficiency.
A knowledgable provider can help you make informed decisions, and tailor treatments to your needs.