Everything You Need to Know About IUDs: How They Work, Side Effects, and More

When it comes to period protection and birth control, there’s nothing more powerful than feeling informed, prepared, and comfortable in your own body. Whether you’re navigating the early days of a new IUD or dealing with those unpredictable spotting moments, having the right support can make all the difference.

That’s why we created Fearless—a line of low-cut, super-stretchy, pastel cheetah print underwear designed specifically for lighter days, spotting, and period weirdness. With a small built-in pad and feel-good fit, Fearless has your back when your birth control journey gets a little unpredictable.

But before we get into that, let’s talk IUDs.

🔍 What Does an IUD Actually Do?

An IUD (intrauterine device) is a tiny, T-shaped piece of plastic placed into your uterus by a healthcare provider. Once it’s in, it works around the clock to prevent pregnancy with more than 99% effectiveness.

There are two main types of IUDs: hormonal and copper. Hormonal IUDs release progestin, which thickens cervical mucus, thins the uterine lining, and sometimes stops ovulation. Copper IUDs don’t use hormones—they rely on copper’s natural ability to prevent sperm from doing their thing.

(Image from PlannedParenthood)

🌟 Why So Many Choose IUDs

• ✅ Long-lasting (3–12 years depending on type)
  
  

• ✅ No daily pills or routines
  
  

• ✅ Highly effective (over 99%)
  
  

• ✅ Can be hormone-free (if you choose copper)
  
  

• ✅ Reversible anytime you want to try for pregnancy
  
  

• ✅ Completely private and discreet
  
  

🌀 The Two Types of IUDs

1. Hormonal IUDs

Brands: Mirena, Kyleena, Liletta, Skyla

• Releases a low dose of progestin (Progestin is a synthetic hormone that mimics progesterone to help regulate the menstrual cycle and prevent pregnancy.)
  
  

• Thickens cervical mucus, thins uterine lining
  
  

• Often lightens or stops periods over time
  
  

2. Copper IUD

Brand: Paragard

• Hormone-free—uses copper to disrupt sperm
  
  

• Can be used as emergency contraception
  
  

• May cause heavier periods initially
  
  

❓Is the IUD the One That Goes in the Arm?

Nope! That’s a common mix-up.

💡 Quick Comparison: IUD vs. Implant

🤕 Is Getting an IUD Painful?

The short answer? It can be—but it's quick. Most people describe it as sharp cramping or pressure that lasts just a few minutes. Everyone’s pain threshold is different, and it also depends on whether you’ve given birth before. Some take pain relievers before their appointment to help ease the experience.

Removal is generally much easier and faster—just a quick tug from your provider and it's out.

⏰ How Often Do You Need to Change Your IUD?

It depends on the type:

When it expires, you can either get it replaced, switch methods, or leave it out if you no longer need birth control.

🔄 Do I Need to Replace It Early?

Sometimes. You may need it removed sooner if you:

• Experience expulsion (it shifts or comes out)
  
  

• Have ongoing pain or side effects
  
  

• Develop an infection
  
  

• Decide to try for pregnancy
  
  

Pro tip: Set a calendar reminder for your expiration date or ask your doctor’s office to follow up. It’s easy to forget it’s even there (which is kind of the point).

⚖️ The Adjustment Phase

Getting an IUD isn’t just a physical change—it’s a hormonal one too (if you're using a hormonal version). It’s totally normal to experience:

• Spotting for several weeks or even months
  
  

• Cramping and mood shifts
  
  

• Changes in period flow (lighter, irregular, or heavier)
  
  

This is exactly where Fearless shines. It’s made for that “in-between” time when you’re bleeding just enough to feel unsure, but not enough to reach for a pad or tampon.

🙋 Common IUD Questions—Answered

Do IUDs stop periods?
Hormonal IUDs often do, especially after a few months. Copper IUDs may make periods heavier or longer, especially early on.

Hormonal IUDs (like Mirena, Kyleena, Liletta, and Skyla) release progestin, a synthetic version of the hormone progesterone. One of the primary effects of progestin is that it thins the lining of the uterus (endometrium). Normally, the uterine lining thickens during your menstrual cycle to prepare for a potential pregnancy. If no pregnancy occurs, the lining sheds, resulting in menstruation.

With a hormonal IUD, the uterine lining doesn’t build up as much, which means there’s less tissue to shed, leading to either lighter periods or no periods at all.

On the other hand, the copper IUD (e.g., Paragard) works without hormones. It relies on copper’s natural properties to create an environment that is toxic to sperm. While it is highly effective at preventing pregnancy, it does not stop periods. In fact, many people with a copper IUD experience:

• Heavier periods: Especially in the first few months, periods may become longer and heavier due to increased uterine lining buildup.
  
  

• More cramping: Copper IUDs may cause more cramping, particularly during menstruation, due to the way they affect the uterus.

So what’s the experience for most people?

• Hormonal IUDs: Many people find that their periods become much lighter or completely stop after 3 to 6 months of use. However, it’s important to note that this doesn’t happen for everyone. Some people may still have light spotting or irregular bleeding for the first few months.
  
  

• Copper IUDs: If you opt for a copper IUD, you can expect to have regular periods, but they may be heavier and accompanied by more cramping.

Can you still get pregnant with an IUD?
Very rarely. IUDs are 99%+ effective. If pregnancy happens, it’s important to get medical attention ASAP due to the risk of ectopic pregnancy.

Does Mirena cause weight gain?
Some users report it, but clinical studies don’t show a strong link. It may vary depending on how your body responds to hormonal changes.

What are the bad side effects of Mirena?
Spotting, irregular bleeding, cramping, acne, and mood changes are common at first. Rare risks include expulsion or uterine perforation.

How much does an IUD cost?
Anywhere from $0–$1,300, depending on insurance. Many plans (including Medicaid) cover it completely—consult, insertion, and follow-ups included.

Where does period blood go when you have an IUD?
Right where it always did—out through your cervix and vagina. An IUD doesn’t block the flow; it just changes how much lining your body sheds.

👙 How Fearless Complements Your IUD Journey

Whether you're in the post-insertion adjustment phase or dealing with random spotting months later, Fearless is made for the moments your IUD keeps you guessing.

Why Fearless Works:

• Low-cut fit that won’t dig in when you’re bloated or crampy
  
  

• Small, built-in pad for light flow and spotting
  
  

• Soft, stretchy fabric that feels like a second skin
  
  

• Pastel cheetah print to add a little playfulness to your routine
  
  

“I got a Kyleena last year and spotted for weeks—Fearless was a lifesaver. I didn’t want to wear a full pad every day, and these were cute and so comfy.” — Sam, 26

💪 Own Your Reproductive Health, Your Way

Choosing an IUD is a bold and empowering decision—and so is choosing period care that makes you feel seen, supported, and comfortable in your own skin. Whether you’re spotting, adjusting to lighter flows, or just embracing your body’s natural rhythm, Fearless helps you live boldly and bleed freely.

Because confidence doesn’t pause for your period.

⚠️ Disclaimer: This article is for informational purposes only and has not been reviewed by a medical professional. Always consult your healthcare provider before making any medical decisions.