When you're in the middle of IVF stimulation, it’s easy to focus on one thing: your follicles. How many? How big? Are they growing?

But here’s the truth: stim hormones affect your entire body, not just your ovaries. That’s why you might feel bloated, foggy, teary, exhausted, or weirdly wired — sometimes all at once.

Let’s take a closer look at what those powerful injections are really doing throughout your body.

First, What Are Stim Hormones?

Most IVF protocols involve daily injections of FSH (follicle-stimulating hormone) and sometimes LH (luteinising hormone). These hormones stimulate your ovaries to produce multiple follicles, each ideally containing a mature egg.

But these hormones don’t stay in one place. They travel through your bloodstream and interact with tissues and systems all over the body.

Your Brain: The Mood + Sleep Centre

• Surging oestrogen levels (from growing follicles) can mess with your mood regulation and sleep-wake cycles.

• You might feel:

  • Extra emotional or teary

  • More anxious or irritable

  • Foggy or forgetful

  • Wired at night and exhausted during the day

💡 You're not losing your mind. You're riding a massive hormonal rollercoaster.

Your Circulatory System: Blood Volume + Heart Rate

• Oestrogen increases blood volume, which can cause:

  • A feeling of fullness or pressure

  • Slightly faster heart rate

  • More flushing or heat

This is one reason why staying hydrated during stims is so important.

Your Breasts & Fluids: Tenderness + Puffiness

• With rising oestrogen, many people notice:

  • Breast tenderness

  • Swollen nipples

  • General puffiness or weight gain (often 1–3kg of water retention)

Your body is holding on to more water and preparing for possible implantation — even before transfer.

Your Muscles & Ligaments: Loosening Up

• High oestrogen can soften connective tissues.

• You might feel:

  • Aches in your hips or lower back

  • A sense of “looseness” or instability

  • More prone to minor injuries if exercising

This is one reason intense exercise is discouraged during stimulation.

Your Digestive System: Bloating + Constipation

• Oestrogen slows down gut motility, while pressure from enlarging ovaries pushes on the intestines.

• Common symptoms:

  • Constipation

  • Feeling overly full, even after light meals

  • Bloating or trapped gas

🫖 Herbal teas (peppermint, fennel) and gentle walks can help.

Your Immune System: Slight Shifts

• While not extreme, IVF stims can slightly modulate immune activity.

• Some people feel:

  • Run down or cold-like

  • More sensitive to stress or infection

  • Slightly inflamed or achy

This is especially relevant if you have an autoimmune condition or chronic inflammation.

Your Skin & Hair: Subtle But Real

• High oestrogen can cause:

  • A dewy glow or unexpected breakouts

  • Skin that’s more sensitive to heat or products

  • Hair that feels thicker — or falls out after the cycle as hormones crash

Everyone responds a little differently.

Summary: You're Not Just “Hormonal” — You're Undergoing a Full-Body Process

Stimulation meds do so much more than grow eggs. They:

• Shift your entire hormonal ecosystem

• Change your metabolism and circulation

• Impact your mood, digestion, sleep, and more

You're allowed to feel off. This is a huge physical and emotional process, and your symptoms are valid — even if your scans look “perfect.”