A dermal filler is a substance that is injected into the skin to add volume and smooth out wrinkles, lines, and other signs of aging. Dermal fillers are typically made from hyaluronic acid, a natural substance found in the body that helps to hydrate and plump the skin, or other materials such as calcium hydroxylapatite or poly-L-lactic acid.

The procedure involves injecting small amounts of the filler into targeted areas of the skin using a fine needle. The filler then adds volume and structure to the skin, resulting in a more youthful and rejuvenated appearance. Dermal fillers can be used to treat a variety of areas on the face, including the cheeks, lips, nasolabial folds, and under-eye area.

The duration of dermal fillers can vary depending on the type of filler used, the location of the injection, and individual factors such as metabolism and lifestyle.

Generally, hyaluronic acid fillers, which are the most commonly used dermal fillers, can last anywhere from 6 to 18 months. The exact duration can depend on the specific brand of filler used and the area of the face or body where it is injected.

Calcium hydroxylapatite fillers can last up to 12 months, while poly-L-lactic acid fillers can last up to 2 years or more.

It's important to note that the effects of dermal fillers are not permanent and that repeated treatments may be necessary to maintain the desired results.

While they are generally considered safe, there are some potential side effects that you should be aware of. Some of the most common side effects of dermal fillers include:

1. Bruising and swelling: Bruising and swelling are common side effects of dermal fillers, especially around the injection site. This typically subsides within a few davs to a week.

2. Redness and tenderness: Injection sites may be red and tender for a few days after the procedure.

3. Itching and rash: Some people may experience itching and a rash around the injection site, which should resolve within a few days.

4. Allergic reaction: Rarely, people may have an allergic reaction to the dermal filler.
   Symptoms may include hives, swelling, and difficulty breathing. Seek medical attention immediately if you experience these symptoms.

5. Infection: Although rare, infection is a possible complication of dermal fillers. Symptoms may include redness, warmth, swelling, and pain around the injection site. Seek medical attention immediately if you experience these symptoms.

6. Lumps and bumps: Sometimes, dermal fillers can result in the formation of lumps and bumps under the skin. These can usually be treated by your healthcare provider.