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How low iron is tied to libido

Want your spark back? Check your ferritin

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June 7, 2026 4:00pm EDT

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FROM DR. BERZIN:

Hormones are critical to getting in the mood, but one overlooked root cause of low libido is not a sex hormone at all: it’s iron. If you’re experiencing sexual dysfunction and only testing for hormonal imbalance, you might be missing something.

Keep reading to learn why we always test ferritin (along with 80+ other markers), and how iron levels might be impacting your sex life.

— Robin Berzin, MD, Founder & CEO, Parsley Health

“Losing that spark” is a medical issue. Find the root cause, and add a clinician visit to plan your next steps and get your groove back.

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Condition Spotlight: Hypothyroidism

Iron status feeds directly into thyroid function. Thyroid peroxidase (TPO), the enzyme responsible for producing thyroid hormones, requires iron to do its job. When ferritin is low, TPO activity is reduced. This suppresses thyroid output even when TSH looks normal on a standard panel.

The result is a compounding effect: low ferritin impairs thyroid hormone production, and low thyroid hormones suppress your libido, deepen your fatigue, and blunt your mood. Unfortunately, conventional medicine is so segmented that many women are treated for one without the other ever being investigated.

Common symptoms of hypothyroidism include persistent fatigue, weight gain, hair thinning, brain fog, low mood, and, yes, low libido.

What is Hashimoto’s thyroiditis? Learn more

Why iron deficiency can decrease your sex drive

Libido is often considered a psychological issue, but the root cause is actually physiological for many women — especially those in midlife.

If you haven’t already gotten sex hormone and thyroid function panels, get them. But don’t stop there; we check nutrients like ferritin along with 80+ other biomarkers to get to the root cause of your low libido.

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Here’s how ferritin and sex drive are connected:

When iron is low, thyroid hormone production is impaired. As discussed in our condition spotlight above, iron deficiency can impair thyroid hormone synthesis and may contribute to symptoms of hypothyroidism. These include decreased libido
Low iron can disrupt testosterone synthesis. Testosterone drives sexual desire for both men and women. When there is less iron available to support steroidogenesis (the process by which the body produces sex hormones), testosterone may be reduced to a suboptimal level.
Iron deficiency triggers a physiological stress response. Elevated cortisol and iron deficiency anemia go hand-in-hand. High cortisol suppresses the HPG axis, the hormonal pathway governing reproductive function. This impacts libido on a neurological level; you won’t be in the mood when you are stuck in “fight” mode.
Low ferritin is associated with reduced dopamine. Dopamine drives motivation and reward, including sexual desire. Iron is a required cofactor for dopamine synthesis.
Iron is essential for energy. When ferritin is low, energy availability drops — and low energy is a consistent predictor of reduced libido.

Read More: 10 Signs You Have a Hormonal Imbalance.

Quick tips for boosting ferritin levels

We work with patients to not only consume more iron, but ensure the body is using it effectively.

1. Eat lots of iron rich foods (red meat, poultry, fish, lentils)
2. Pair iron-rich foods with vitamin C
3. Avoid coffee, tea, red wine, and calcium-rich foods when eating iron (they may inhibit absorption)
4. Consider supplementation (under medical supervision)
5. Work with a clinician to find underlying causes of malabsorption

Read More: What Causes Low Ferritin

BIOMARKER SPOTLIGHT

Ferritin

Standard iron testing usually focuses on hemoglobin or serum iron. The problem is that these only tell you what's circulating in your blood at the moment, and that can fluctuate based on recent meals, your menstrual cycle, and acute inflammation, meaning that it’s a less reliable standalone measure.

Ferritin is the protein that stores iron throughout the body. We test it because it provides a more complete picture of your long-term iron reserves, and low ferritin often appears months or even years before iron deficiency anemia develops.

Test ferritin along with 80+ other biomarkers to find the root cause of low libido, and review results with a functional medicine clinician.

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What We're Taking (and Why)

Thyroid Balance

If low ferritin is impairing TPO activity and suppressing your thyroid output, your first step is to address iron levels. Then, you can give the thyroid what it needs to function optimally. Thyroid balance provides nine clinically dosed nutrients that support thyroid hormone production from multiple angles.

Iodine and selenium — in its most bioavailable form, selenomethionine — are essential for hormone synthesis and T4-to-T3 conversion
Zinc protects the thyroid from oxidative damage
Vitamins A, D, and E support hormone signaling and antioxidant defense
Rhodiola rosea is an adaptogenic herb that addresses fatigue stress

Shop Thyroid Balance

“My thyroid numbers were up. I took this for a few months, and things were back on my last bloodwork results.”
- Melanie W.

What members are saying:

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“Working with Ashley at Parsley Health has genuinely changed how I approach my health. She looks at the full picture — labs, hormones, thyroid, lifestyle — and builds a protocol that adapts as new data comes in. When my labs shifted, she didn't just adjust the prescription and move on; she walked me through the reasoning and what to watch for.”

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