The instructions for use that come with a dermal filler are not marketing material. They are a regulatory document, and in a complaint or a claim they are one of the first things anyone will ask whether you followed. Most practitioners glance at them once and never again. It is worth learning to read them properly.
Start with the intended use section. This tells you what the manufacturer has actually tested and declared the product for, which is often narrower than what the product gets used for in practice. A filler indicated for deep dermal injection for the correction of nasolabial folds has been assessed for that. Using it somewhere else is not automatically wrong, but it is off label, and off label means the clinical justification is now yours rather than the manufacturer's. You should be able to explain why you chose it, and that explanation should appear in your notes.
Next, look at the contraindications. These are usually short and are worth committing to memory for the products you use most. Autoimmune conditions, active infection at the site, known hypersensitivity to any component, pregnancy and breastfeeding appear on most. Where a product lists something unusual, that is the manufacturer telling you about something they saw in testing.
The injection depth and technique section matters more than people give it credit for. Different products in the same range are formulated for different planes. A thicker product placed too superficially will show, and a thin product placed too deep will do nothing you wanted. If your result looks wrong and you cannot work out why, the depth stated in the document is a reasonable place to start looking.
Pay attention to the warnings about vascular events. Since the middle of the last decade almost every manufacturer has strengthened this language considerably. Read what they say about injection pressure, about moving the needle, and about what to do if the patient reports pain out of proportion to the procedure. Manufacturers are cautious with this wording, and when they say something specific it is usually because a pattern was reported to them.
The storage and handling section is dull and occasionally important. Temperature ranges, whether a product can be returned to the fridge once it has come to room temperature, whether the syringe can be part used. If you have ever wondered whether it is acceptable to keep a half syringe for a top up in two weeks, the answer is in there, and it is usually no.
Finally, check the lot number and expiry, and record both. This is the documentation gap that turns up more than any other. If a product is ever recalled, or if a patient develops a delayed nodule eighteen months later, the batch is the thread that ties everything together. Writing it down takes five seconds. Reconstructing it afterwards is often impossible.
When you take on a new product, read the document once properly and keep a copy somewhere you can actually reach. Not filed in a drawer under other paperwork. Somewhere you could grab one handed while you are on the phone.