The goal of this research study is to learn more about how different uses of a numbing medication might affect pain levels while getting an IUD placed. The investigators are also studying patients' opinions of their clinicians' empathy.

The investigators are inviting patients who have never given birth who arrive at their clinic visit seeking an IUD.

Usually, at University of California, San Diego (UCSD), for patients who have never delivered, clinicians numb both the sides of the cervix with a lidocaine-based paracervical block. The purpose of this research study is to compare perceptions of pain between buffered (2 cc of sodium bicarbonate, 18 cc of 1% lidocaine) vs. unbuffered paracervical block (20 cc 1% lidocaine) during IUD placement for nulliparous women.

Lidocaine is a drug that has been approved by the Food and Drug Administration (FDA). Sodium bicarbonate is an additive that buffers the acidity of lidocaine. The combination of the two is safe and effective as a paracervical block for pain relief in various OBGYN procedures. At UCSD and other places, it is currently standard practice for people with no prior deliveries to receive a buffered lidocaine paracervical block prior to IUD placement.

Participants who take part in this study, will be randomly assigned to receive an injection of buffered lidocaine OR an injection of unbuffered lidocaine to numb the area before IUD placement.

Throughout the local anesthetic and intrauterine device (IUD) placement procedure, research team members will question participants about their pain levels, their satisfaction with the procedure, and how much empathy they feel the clinician has shown.

Inclusion Criteria:

1. Ability to provide informed consent
2. Women IUD placement for contraception or heavy menstrual bleeding
3. Ages 18-50
4. English-speaking
5. Participants must not have a past medical history of substance use disorders, pain disorders, use of prescription pain medications or are found to be pregnant
6. Nulliparous (never given birth)

Exclusion Criteria:

1. History of ever giving birth
2. Current use of prescription pain medication prior to procedure. Over-the-counter medications such as those containing ibuprofen, aspirin, acetaminophen, or naproxen are allowed.
3. Diagnosed chronic pain condition
4. Current pregnancy
5. Known allergic reactions to components of the local anesthetic
6. History of an IUD placement
7. Current substance use or history of substance use
8. Known contraindications to IUD, such as unexplained vaginal bleeding

Participants will not know their group assignment. The clinicians will know which group the participant is in, because they will be preparing the buffered or unbuffered lidocaine injection.