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Thinning, shedding, and feeling like your hair is betraying you? If you have hypothyroidism or Hashimoto’s, you know the frustration all too well. Hair loss isn’t just physical—it hits your confidence hard. But here’s the good news: science is catching up, and new hair restoration solutions are making waves! Enter minoxidil—the powerhouse behind Rogaine—which is now being used in both oral and topical forms to help regrow hair, including for those dealing with thyroid issues. In this article, we’re diving into the latest research and how this game-changing treatment could be your secret weapon against hair loss.
Hair growth occurs in a cyclical process consisting of four main phases.
- The anagen phase is the active growth stage, lasting 2 to 8 years, during which hair grows approximately 1 to 1.5 cm per month.
- This is followed by the catagen phase, a short transitional period lasting 1 to 2 weeks, where hair growth slows and follicles begin to shrink.
- The telogen phase is the resting stage, lasting 3 to 4 months, during which hair remains dormant in the follicle.
- Finally, the exogen phase, also known as the shedding phase, occurs when old hairs are released, making way for new growth. This cycle repeats continuously, with each hair follicle operating independently, ensuring that not all hairs are in the same phase simultaneously.
Hypothyroidism and Hashimoto’s thyroiditis, an autoimmune condition that often leads to hypothyroidism, can cause significant changes in your hair health. Common types of thyroid-related hair loss include:
- Diffuse thinning (telogen effluvium) – Widespread hair shedding due to disrupted hair growth cycles caused by thyroid hormone imbalances.
- Brittle, dry hair – Hair becomes dry, coarse, and prone to breakage due to decreased thyroid function, which affects oil production.
- Frontal and temporal thinning – Hair loss concentrated around the hairline and temples, similar to androgenic alopecia but linked to thyroid dysfunction.
- Alopecia areata – Patchy hair loss caused by an autoimmune response, which can co-occur with Hashimoto’s thyroiditis.
- Eyebrow thinning (especially the outer third) – A hallmark sign of hypothyroidism where the outer edges of the eyebrows thin significantly.
- Reduced hair regrowth – Slower hair regrowth due to impaired follicle function and prolonged resting phases.
- Body and eyelash hair loss – In severe cases, hair loss can extend to body hair and eyelashes due to prolonged thyroid imbalance.
The underlying causes of thyroid-related hair loss include insufficient thyroid hormone levels, autoimmune inflammation, and disruptions in the hair growth cycle. Hair follicles depend on an optimal balance of thyroid hormones—particularly the active hormone triiodothyronine (T3) and the storage hormone thyroxine (T4)—to stay in the active growth (anagen) phase. When this balance is disrupted, more hair follicles enter – and often remain in – the telogen resting phase, resulting in shedding.
Minoxidil was initially developed as an oral medication for high blood pressure. It was found to have an unexpected side effect: hair growth. This led to the development of topical minoxidil products like Rogaine, which have been FDA-approved for androgenetic alopecia (male and female pattern hair loss). More recently, low-dose oral minoxidil (LDOM) has gained attention as an off-label option for various types of hair loss. (Off-label means that the FDA hasn’t explicitly approved it for this purpose, but it can be prescribed at a doctor’s discretion.)
Both forms of minoxidil work by:
- Prolonging the anagen phase: Extends the growth phase of hair follicles.
- Increasing blood flow: Improves scalp circulation, delivering nutrients and oxygen to hair follicles.
- Stimulating follicular activity: Encourages dormant follicles to produce new hair.
Topical minoxidil is FDA-approved for treating male and female pattern baldness. It is typically available in 2% and 5% concentrations, and the lower potency version is available over the counter. Topical minoxidil has been a go-to treatment for many types of hair loss.
Clinical trials have demonstrated that topical minoxidil can significantly improve hair density and thickness. For women using 5% topical minoxidil, studies indicate an increase in scalp hair by approximately 14% to 18% after one year of treatment.
The effectiveness of topical minoxidil for hair loss in Hashimoto’s and hypothyroid patients has been supported by anecdotal evidence and some clinical observations indicating that it may help accelerate regrowth once thyroid hormone levels are stabilized.
Topical minoxidil has several benefits for people experiencing hair loss:
- Increased hair density: Various studies show that 5% topical minoxidil significantly increases hair density and thickness after 24 weeks of use.
- Reduced shedding: Patients with telogen effluvium – a common side effect of Hashimoto’s and hypothyroidism – report noticeable reductions in hair shedding after three months of twice-daily application.
- Minimal systemic absorption: Because topical minoxidil primarily acts on the scalp, systemic side effects are rare, making it a safer option for individuals with other health conditions.
Topical minoxidil requires the consistent, long-term application to maintain results. Some users experience initial shedding during the first few weeks, which can be alarming but is generally a sign that the medication is stimulating new growth. Minoxidil also requires continuous use to maintain the effects.
Apart from the shedding, topical minoxidil can cause several other effects, ranging from common and mild to rare and more serious. Common side effects include:
- Scalp irritation, itching, dryness, scaling, flaking, or burning
- Redness at the application site
Less common side effects include:
- Unwanted facial or body hair growth
- Acne at the site of application
Rare but serious side effects may occur if higher amounts of the medication are absorbed into the bloodstream. They include:
- Chest pain or fast heartbeats
- Dizziness or lightheadedness
- Swelling of hands, feet, or face
- Rapid weight gain
- Difficulty breathing, especially when lying down
- Headache or confusion
- Blurred vision
If you experience any serious side effects or signs of an allergic reaction (such as hives, difficulty breathing, or swelling of the face, lips, tongue, or throat), stop using minoxidil and seek immediate medical attention.
While topical minoxidil has been widely used for years, recent research has explored the benefits of off-label use of low-dose oral minoxidil (LDOM) for hair loss, including when it’s related to thyroid disorders. Oral minoxidil works by enhancing blood circulation to hair follicles and prolonging the anagen phase of hair growth. It may also have systemic effects that could benefit overall scalp health.
Unlike topical formulations, LDOM works systemically, offering some advantages:
- Convenience: Oral minoxidil eliminates the need for daily scalp application, appealing to those who find topical treatments messy or time-consuming.
- Broader effectiveness: Some individuals who don’t respond well to topical minoxidil experience better results with the oral version.
Oral minoxidil is particularly appealing for patients who may prefer a systemic treatment over daily topical applications. LDOM has been prescribed off-label by dermatologists worldwide due to its effectiveness.
Studies have shown promising results for LDOM in promoting hair growth. A retrospective case series indicated that patients receiving low doses (typically between 0.25 mg to 5 mg daily) experienced increased scalp hair growth and decreased shedding rates. The reported success rates vary but often exceed 65% among users.
LDOM can cause several potential side effects, ranging from common and mild to rare and more serious. Common side effects include:
- Hypertrichosis: The most frequent side effect, occurring in about 15.1% of patients, is increased hair growth on the face, arms, and back
- Lightheadedness: Reported in approximately 1.7% of patients
- Fluid retention: Affects about 1.3% of patients, potentially leading to bloating and swelling of feet or lower legs
- Tachycardia (fast heartbeat): Observed in 0.9% of patients
- Headache: Affects 0.4% of patients
- Periorbital edema: Swelling around the eyes, seen in 0.3% of patients
- Insomnia: Reported in 0.2% of patients
The less common side effects include:
- Numbness or tingling of hands, feet, or face
- Chest pain or shortness of breath
- Skin rash and itching (rare)
- Breast tenderness in males and females
Although rare, more serious side effects can occur, including:
- Pericardial effusion: Reported as a common adverse effect (3% to 5%) in the package inserts for commercial oral minoxidil used for treating hypertension
- Angina: Minoxidil may worsen this condition
- Potential complications in patients with heart or blood vessel disease, as minoxidil can cause fluid buildup
It’s important to note that while these side effects are potential risks, LDOM generally has a good safety profile. In a large study, only 1.7% of patients discontinued treatment due to the adverse impacts.
Hypothyroidism occurs when the thyroid gland does not produce enough thyroid hormones, leading to a slowdown in metabolism and various symptoms, including fatigue, weight gain, and hair loss. Hashimoto’s disease is the most prevalent cause of hypothyroidism and is characterized by an autoimmune attack on the thyroid gland. The resultant hormonal imbalance can disrupt the hair growth cycle, leading to diffuse hair thinning of hair on the head and body rather than localized bald spots.
Patients with thyroid-related hair loss often experience telogen effluvium, where hair follicles prematurely enter the resting phase of the growth cycle. This can result in significant shedding, particularly during periods of stress or hormonal fluctuation.
In addition, a telltale sign of hypothyroidism in some patients is loss of hair from the outer edge of the eyebrows.
Successful management of thyroid-related hair loss usually requires a multi-faceted approach. Combining minoxidil with optimized thyroid hormone therapy can yield good results for many thyroid patients.
Optimizing thyroid hormone levels
Ensuring that thyroid stimulating hormone (TSH), free thyroxine (free T4), and free triiodothyronine (free T3) levels are optimized is crucial. Both over- and under-treatment of hypothyroidism can worsen hair loss and slow hair regrowth.
Thyroid hormone replacement therapy can help some patients achieve hair regrowth after achieving stable thyroid hormone levels. In some cases, patients who have continued hair loss on a levothyroxine (T4-only) treatment experience reductions in their hair loss when optimized by adding T3 to their treatment in the form of synthetic T3 medication (liothyronine) or by using a natural desiccated thyroid (NDT) drug.
Once thyroid hormone levels are restored and optimized through appropriate treatment, hair regrowth can typically begin within several months in many hypothyroid patients.
Learn more about the connection between thyroid dysfunction and hair loss and how to stop it in this video featuring Paloma endocrinologist Yasmin Akhunji, MD, and dietitian Whitney Crouch, RDN, “How To Stop Hair Loss With Hypothyroidism.”
Addressing nutritional deficiencies
Nutritional factors heavily influence hair health. Common deficiencies in hypothyroidism include the following:
- Iron: Low ferritin levels are linked to increased hair shedding. Supplementation can enhance the efficacy of minoxidil.
- Biotin: Biotin is often included in hair supplements.
- Zinc and selenium: Essential for thyroid function and hair follicle health.
Thyroid patients who ensure their diet includes these nutrients may notice reduced hair loss.
Minoxidil and related therapies
Combining minoxidil with other treatments may improve outcomes for thyroid-related hair loss:
- Platelet-rich plasma (PRP) therapy: PRP injections can stimulate hair follicles and enhance the effects of minoxidil.
- Low-level laser therapy (LLLT): Devices like laser caps promote scalp blood flow and support hair regrowth
- Spironolactone: Some studies suggest that combining oral minoxidil with other treatments like spironolactone may enhance efficacy while mitigating side effects.
Topical minoxidil can be used on the eyebrows to promote hair growth, but it’s an off-label use. However, many people have reported positive results using 2% or 5% minoxidil on their eyebrows. Topical minoxidil may promote thicker, fuller eyebrow growth over time, and some users see noticeable results in 2 to 3 months, with maximum results around 6 months to a year.
Here are some tips on how to safely use topical minoxidil on your eyebrows:
- Cleanse your face and ensure your eyebrows are dry.
- Use a small amount (a drop or less) and apply it with a clean cotton swab or a precision brush to the eyebrow area. - Accidental eye exposure can cause irritation.
- Apply once daily (at night is best to avoid rubbing it off).
- Avoid contact with eyes and do not apply to broken or irritated skin.
- Be patient—results take weeks to months.
- Stop use if irritation occurs or if unwanted hair growth appears in surrounding areas.
If you have sensitive skin or any concerns, consult a dermatologist before trying it.
There isn’t robust scientific evidence specifically focusing on oral minoxidil for eyebrow hair loss. However, oral minoxidil stimulates hair follicles, potentially supporting regrowth in areas with thinning or sparse eyebrows.
Here are some practical tips if you have already optimized your thyroid treatment and are considering minoxidil as part of your hair restoration regimen.
Topical minoxidil
- Start with 5%: Most studies suggest that 5% minoxidil – which requires a prescription -- is more effective than lower concentrations available over the counter.
- Apply to a dry scalp: Ensure your scalp is clean and dry before application to enhance absorption.
- Be patient: Visible results may take 3-6 months.
Oral minoxidil
- Consult a specialist: Work with a dermatologist or endocrinologist who is experienced in prescribing LDOM.
- Monitor side effects: Report any unusual symptoms, such as swelling or excessive hair growth, to your healthcare provider.
The intersection of thyroid health and hair restoration is an area of growing interest. Future studies may focus on:
- Personalized treatment plans: Identifying genetic or hormonal markers that predict response to minoxidil.
- Combination therapies: Exploring synergies between minoxidil, thyroid hormone therapy, and other hair growth stimulants.
- Long-term safety of oral minoxidil: Establishing comprehensive safety profiles for prolonged use in diverse populations, including Hashimoto’s and hypothyroid patients.
Hair loss associated with hypothyroidism and Hashimoto’s thyroiditis can be challenging, but recent advancements in oral and topical minoxidil offer promising solutions. For thyroid patients, minoxidil, in combination with thyroid hormone optimization and nutritional support, can make a big difference for your hair, helping you restore confidence and improve your quality of life. As research continues, personalized and effective treatment options are becoming more accessible, paving the way for even better outcomes in the future.
Taking control of your thyroid health is the first step toward restoring your hair and overall well-being. As a Paloma Health member, you’ll have access to expert thyroid specialists, personalized treatment plans, and comprehensive support designed specifically for people with hypothyroidism. By optimizing your medication, monitoring key thyroid levels with Paloma’s convenient home thyroid test kits, and addressing important nutritional and lifestyle factors, you can create the ideal conditions for hair regrowth and improved health. Don’t settle for a one-size-fits-all approach—partner with Paloma Health to get the care you deserve and take charge of your thyroid journey today.
- Hypothyroidism and Hashimoto’s can disrupt the hair growth cycle, leading to thinning, shedding, and brittle hair.
- Hair follicles rely on thyroid hormones (T3 and T4) to stay in the active growth phase, and imbalances can trigger increased shedding.
- Minoxidil, the active ingredient in Rogaine, is available in both topical and oral forms to help stimulate hair regrowth.
- Topical minoxidil is FDA-approved for pattern baldness and has shown promising results for thyroid-related hair loss with consistent use.
- Low-dose oral minoxidil (LDOM) is an emerging off-label treatment that improves blood flow to hair follicles and may be more effective for some patients.
- Optimizing thyroid hormone levels, addressing nutritional deficiencies, and combining treatments like PRP or laser therapy can enhance hair regrowth.
- Minoxidil can also be used off-label for eyebrow regrowth, but results take time and require careful application.
- While minoxidil is generally safe, potential side effects include scalp irritation (topical) and increased body hair growth or fluid retention (oral).