How long does swelling from a lip piercing las?

Usually it gos by the person, but it can last up for a few weeks. Putting a ice pack on the lip will help but sometime only for the first 24 hours. Using an anti inflammatory like Ibuprofen(advil, motrin) can help reduce the swelling. Sea salt soaks also help.

Sea Salt soak: To perform the sea salt soak, 1. Wash your hands thoroughly with liquid antibacterial or antimicrobial soap. 2. Place a pinch of sea salt in the bottom of a small disposable cup. About 1/8 teaspoon.
3. Add hot tap water - as hot as you can stand - to the salt. Use about 3 ounces of water - which is just over half-full in a 5 ounce cup.
4. If possible, invert the cup right over the piercing and allow it to stay there for 5 minutes. This usually works well for nipple and navel piercings. If you can't create a sufficient seal against the skin with the cup, then soak a cotton ball in the salt water solution and apply the cotton ball to the piercing. When it cools down, throw it away and place a newly saturated cotton ball on the piercing. Do this for 5 minutes. 5. Rinse the piercing with warm water and dry with a clean paper towel.

Tips

• ONLY pure sea salt is to be used. Table salt, kosher salt, epsom salts, and iodized sea salts are not acceptable. Sea salt can be found in many grocery stores and almost all health food stores.
• If you are not sure about the solution strength, put a dab on your finger and taste it with the tip of your tongue. It should be no saltier than a potato chip.
• To aid in healing a new piercing, sea salt soaks once a day should be sufficient. If your piercing is irritated, increase sea salt soaks to 2-3 times per day until the irritation subsides.
• If your piercing becomes irritated as a result of sea salt soaks, you are probably using either the wrong kind of salt or have made your solution too strong.