792. Three Numbers That Tell Me More Than Your Doctor’s Entire Thyroid Workup

In this episode, I dig into one of the most frustrating things I see women struggle with: being told their thyroid is “fine” based on a single number, while they’re still dealing with fatigue, weight gain, hair thinning, brain fog, and feeling cold all the time.

Here’s what I want you to take away:

TSH isn’t a full thyroid test. It’s just a signal from your brain to your thyroid—not a measurement of what your body is actually producing or whether your cells can use it. The “normal” range is so wide you could drive a Mack truck through it. Normal doesn’t mean optimal.

The numbers I actually look at:

  • Free T3 – the active hormone your cells actually use. It’s the one that matters most and almost never gets tested. You can have plenty of T4 (the storage form) and still feel awful if you’re not converting it.
  • Reverse T3 – I think of this as the brake pedal that stress slams on. It’s a mirror-image molecule (like your left hand vs. your right) that parks in your receptors and blocks the active hormone from getting in. Chronic stress, low iron, illness, crash dieting, and inflammation all push your body to make more of it.
  • TPO and TG antibodies – these can rise 7 to 10 years before your TSH ever moves. Catching Hashimoto’s early gives you a window to address the root drivers.

It’s never just one thing. Your thyroid gets ambushed—inflammation, stress, nutrient deficiencies, gut issues—all stacked and compounded over time. This is especially true in perimenopause, when rising cortisol, falling ferritin from heavy periods, and lower stomach acid all converge. That’s why so many women hit a thyroid crash in their 40s.

A real story from my own life: I went in for a checkup and asked to have my antibodies retested (I have a history of Hashimoto’s). My doctor physically couldn’t add the lab to my file because the system only allows it once—even though my previous result was out of range. This isn’t about one bad doctor; the system isn’t built to support you. I now have to order my own labs through an outside lab.

What your body needs to convert T4 to T3: selenium, zinc, iron, and a calm nervous system. These nutrients are commonly depleted in women, especially with a history of oral birth control. And food is the most bioavailable source—so variety matters. Eating the same meal-prepped chicken and broccoli every week can leave you deficient.

A word on supplements: more isn’t better. I recently had to remove several supplements from a client’s routine because they were overloading her with B vitamins and depleting her minerals. Expensive and fancy doesn’t mean right for your body.

My bottom line: You have to be the driver of your own health. Look back through your old labs right now and check whether your antibodies and Free T3 have ever been tested. If you’ve been struggling for six months or more, take action. Your body has an incredible ability to heal when we test properly, look at the whole picture, and give it the right things at the right time.

If you need help figuring out your next steps, the link to schedule a strategy call with my team is in the show notes. You’re not too far gone—you’re closer now than you were before you knew this!

👉 https://calendly.com/dr-beth-westie/program-discovery-call

👉 Download your FREE Hormone Cascade Map here: https://dr-beth-westie.mykajabi.com/hormone-cascade-map