The surprising role of progesterone for your thyroid function
By Dr. Sarika Arora,
It’s really frustrating when you have symptoms of low thyroid but your thyroid test
results are still in the “normal” range.
You want relief from your suffering but your doctor says there’s nothing wrong with
This happens all too often. The truth is this: in many cases a contributing factor
to thyroid dysfunction is imbalanced sex hormones.
If this is you, the good news is that we can get you back on track quickly once
we’ve confirmed my suspicions. Let’s start by looking at how the thyroid fits into
your endocrine system.
Hormonal imbalance can trigger thyroid symptoms at any age
Sex hormones — especially progesterone — can have a surprisingly powerful influence
on the activity and effectiveness of thyroid hormones. Imbalanced reproductive hormones
lead to hypothyroid symptoms — weight gain, low energy, hair loss — even when your
lab tests are in the normal range.
When your hormones shift, progesterone levels often drop too low. The healthy hormonal
balance between estrogen, testosterone and progesterone often changes after childbirth,
during perimenopause/menopause, and while using oral contraceptives. The end result
is higher estrogen levels that are out of proportion to the other sex hormones.
When estrogen is high and progesterone is low (a state known as “estrogen
dominance”), your liver increases production of a protein called thyroid
binding globulin (TBG). TBG is released into the blood and binds free thyroid hormone
(T3 and T4) before it can reach your cells to do its work.
So even though your thyroid panel may appear normal, your thyroid hormones are being
held captive because they are bound to TBG. This makes your thyroid hormone unavailable
to be used by your body and eventually causes symptoms of hypothyroidism.
Does just adding progesterone improve thyroid function? Not exactly.
Many healthcare practitioners suggest supplemental progesterone when women have
estrogen dominance. One study found that postmenopausal women who supplemented with
300 mg/day of micronized progesterone had increased levels of free thyroid hormone
Yet, simply adding one hormone to balance another doesn’t usually get to the root
of what caused the imbalance. And for some women, this kind of hormone replacement
isn’t a long-term solution.
For my patients who are experiencing estrogen dominance, I often start with herbs
like black cohosh, ashwagandha and chasteberry. These herbs help the body rebalance
estrogen, testosterone and progesterone naturally before we even need to consider
supplemental hormone treatment.
After the patient tries a combination of
supplemental herbs, a
high-quality multivitamin and lifestyle changes, the production of TBG
in the liver is often turned down, which allows thyroid hormones to enter her cells
the way they should. When this happens, thyroid symptoms often subside and her life
returns to normal.
Other tips to rebalance hormones and resolve low thyroid symptoms
If you’re struggling with hypothyroid symptoms, while your thyroid tests remain
in the normal range, investigate the possibility of a sex hormone imbalance before
taking other measures.
You can begin to rebalance your hormones by following these steps:
- Upgrade your nutrition. Good hormonal balance begins
with a fresh, whole foods diet. Include plenty of fresh vegetables, healthy fats
(avocado, salmon, olive oil) and lean proteins.
- Start strength training. Building muscle burns body
fat. Since fat produces estrogen, building muscle helps reduce estrogen dominance.
Make movement a priority and incorporate full body strength training 2-3 days per
- Create stress-relieving rituals. High levels of daily
stress disrupt both your sex hormone balance and your thyroid hormones. Take time
to notice the things that cause you stress. Surprisingly simple steps can lighten
your stress load and allow your body to rebalance itself. I recommend self care
Sundays that include yoga, meditation, and reading a great book.
For more information about the natural approach to resolving hypothyroidism, see
our article Five
steps for natural thyroid symptom relief.
How does hormonal imbalance in perimenopause
and menopause affect your thyroid? Find out with our article on
Hypothyroidism in menopause.
Sathi P, et al. “Progesterone therapy increases free thyroxine levels—data from
a randomized placebo-controlled 12-week hot flush trial. Clin Endocrinol (Oxf),
2013 Aug 79(2):282-7. Abstract URL: https://www.ncbi.nlm.nih.gov/pubmed/23252963