Tests for PCOS Weight Loss Resistance: What to Check When Nothing Is Working

Tests for PCOS Weight Loss Resistance: What to Check When You’re Doing Everything “Right”

If you have PCOS and weight loss feels impossible, it’s not because you’re not trying hard enough.

I see this constantly:Women are eating well, training consistently, cutting back on sugar, tracking steps… and still not seeing results.

Or worse, they’re doing extreme diets, over-exercising, skipping meals, feeling exhausted… and the scales still don’t move.

This is where I want you to understand something that can shift everything:

When PCOS weight loss isn’t happening, it’s usually not a motivation problem. It’s a metabolic/hormonal driver problem.

And the best way to identify the driver is testing.

Not random tests.Not everything at once.The right tests in the right order.

This blog breaks down the most important tests to investigate when weight loss is resistant with PCOS, and why “normal results” don’t always mean your body is functioning optimally.

Someone getting a blood test

Why Testing Matters With PCOS Weight Loss

PCOS weight loss resistance can be driven by:

• insulin resistance

• inflammation

• thyroid dysfunction

• cortisol dysregulation

• androgen excess

• nutrient depletion

• poor ovulation and low progesterone patterns

Testing helps you:

• stop guessing

• understand what’s driving fat storage

• tailor food and training properly

• identify issues early before they worsen

• save money long term by being strategic

The Most Important Tests for PCOS Weight Loss Resistance

1) Fasting Insulin (This Is the Big One)

This is one of the most missed drivers.

Most women only get glucose tested — but insulin resistance begins long before glucose becomes abnormal.

Ask for:

• fasting insulin

• fasting glucose

• HbA1c

Why it matters: High insulin encourages fat storage and blocks fat burning. If insulin is high, weight loss will feel like pushing uphill.

2) Full Thyroid Panel (Not Just TSH)

Thyroid dysfunction can slow metabolism, worsen fatigue, increase water retention and make weight loss far harder.

Ask for:

• TSH

• free T4

• free T3

• TPO antibodies

• thyroglobulin antibodies

Symptoms suggesting thyroid involvement include:

• fatigue, cold intolerance

• constipation

• hair thinning

• low motivation

• stubborn weight gain despite effort

3) Androgen Panel

Androgen excess is a common PCOS driver, and it interacts heavily with insulin resistance.

Ask for:

• total testosterone

• free testosterone

• SHBG

• DHEA-S

• (optional) androstenedione

Why it matters: Higher androgen activity can worsen abdominal fat storage and make insulin resistance harder to improve.

Also, low SHBG often signals metabolic dysfunction and increased free androgen activity even when testosterone “looks normal.”

4) Inflammation Markers

Inflammation worsens insulin resistance and can keep the body in a state where it resists weight loss.

Ask for:

• hs-CRP

• ESR (if indicated)

• 
  

Inflammation also drives fatigue, cravings and water retention all of which affect progress.

5) Liver Function Tests

This one is overlooked, but it matters.

The liver plays a huge role in:

• blood sugar regulation

• hormone clearance

• inflammation control

Ask for:

• ALT

• AST

• GGT

In PCOS, fatty liver changes can occur even in women who aren’t classified as overweight — and it can impact metabolism significantly.

6) Lipid / Cholesterol Panel

PCOS is a metabolic condition, and lipids can show early metabolic strain.

Ask for:

• total cholesterol

• LDL

• HDL

• triglycerides

Triglycerides and low HDL can be metabolic red flags for insulin resistance.

7) Iron Studies + Ferritin

Low iron doesn’t just affect energy — it affects training performance, recovery and motivation.

Ask for:

• iron studies

• ferritin

Fatigue and depletion make PCOS weight loss harder simply because the body can’t sustain the habits needed for progress.

8) Vitamin D

Vitamin D impacts inflammation, insulin sensitivity and hormone signalling.

Ask for:

• 25-OH vitamin D

• 
  

Low vitamin D is extremely common and often missed.

9) B12 and Folate

These influence energy production, mood and metabolic pathways.

Ask for:

• B12

• folate

• 
  

If you’re exhausted, flat, and relying on caffeine, these matter.

10) Progesterone (If Cycles Are Irregular)

If ovulation isn’t occurring consistently, progesterone will be low — and low progesterone patterns can affect:

• sleep quality

• mood stability

• stress resilience

• hunger regulation

Progesterone should be tested:

• 7 days after ovulation(not just “day 21” unless you have a textbook 28-day cycle)

Why “Normal Results” Can Still Mean Weight Loss Resistance

This is where women get understandably frustrated.

You can be told: “Everything looks fine.”

But if you still have symptoms and weight is resistant, it usually means:

• the wrong markers were tested

• the results weren’t interpreted in context

• reference ranges were used as the only guide

• key ratio patterns were missed (insulin, androgens, thyroid conversion, SHBG)

PCOS weight loss requires deeper interpretation.

What To Do After Testing

Once the root driver is identified, weight loss becomes clearer and less frustrating.

Your next step is creating a plan that supports:

• insulin sensitivity

• inflammation reduction

• thyroid function

• nutrient replenishment

• nervous system regulation

• 
  

When those foundations shift, weight loss becomes a side effect of healing, not a constant fight.

Final Thoughts

If you have PCOS and weight loss isn’t working, it doesn’t mean you’re doing something wrong.

It usually means your body is asking for deeper support.

Testing gives you clarity.And clarity creates progress.

If you feel like you’re doing everything “right” and still not seeing results, you don’t have to keep guessing.

Book a FREE Naturopathic PCOS Assessment Call and we’ll map out what’s driving your weight loss resistance, what tests to prioritise, and the next steps to improve insulin sensitivity, reduce inflammation and support hormones so your body finally responds.