Underactive thyroid and thinning hair
Pro Research Analysisby 
Searched over 200M research papers
Underactive Thyroid and Thinning Hair: Understanding the Connection
Thyroid Hormones and Hair Follicle Function
Thyroid hormones, specifically triiodothyronine (T3) and thyroxine (T4), play a crucial role in the regulation of hair follicle (HF) functions. Research has shown that these hormones directly influence the proliferation and apoptosis of hair matrix keratinocytes, which are essential for hair growth and maintenance1. T4, in particular, has been found to prolong the anagen phase, the active growth phase of hair, by down-regulating TGF-beta2, a key inhibitory growth factor1. This suggests that adequate levels of thyroid hormones are necessary for maintaining healthy hair growth cycles.
Impaired Hair Growth in Hypothyroidism
Hypothyroidism, a condition characterized by insufficient thyroid hormone production, has been linked to various hair disorders. Clinical observations and experimental studies indicate that hypothyroid patients often experience thinning of the epidermis and alopecia, a condition marked by significant hair loss2. Mice studies have further demonstrated that the absence of thyroid hormone receptors (TRα1 and TRβ) leads to impaired hair cycling and reduced follicular cell proliferation, reinforcing the importance of thyroid hormones in hair growth2. These findings highlight the critical role of thyroid hormone receptors in maintaining normal hair growth and skin homeostasis.
Prevalence and Impact of Thyroid Dysfunction on Hair Loss
Thyroid dysfunction, including both hyperthyroidism and hypothyroidism, is strongly associated with various types of hair loss, such as telogen effluvium, alopecia areata, and androgenetic alopecia3. The skin, being a significant target organ for thyroid hormones, is adversely affected when thyroid hormone levels are imbalanced. This can lead to widespread hair shedding and other hair disorders3. Despite the clear link between thyroid dysfunction and hair loss, the prevalence and specific impacts of these conditions are often underestimated. More research is needed to fully understand the cellular and molecular mechanisms behind thyroid dysfunction-related hair disorders and to improve diagnosis and management strategies3.
Conclusion
The relationship between thyroid hormones and hair health is complex and significant. Adequate levels of T3 and T4 are essential for the proper functioning of hair follicles, influencing both the growth phase and pigmentation of hair. Hypothyroidism can lead to impaired hair growth and increased hair loss, underscoring the importance of thyroid hormone receptors in hair follicle regulation. Understanding the prevalence and impact of thyroid dysfunction on hair disorders is crucial for developing better diagnostic and treatment approaches. Further research is necessary to bridge the gaps in knowledge and enhance the management of hair disorders associated with thyroid dysfunction.
Sources and full results
Most relevant research papers on this topic
Thyroid hormones directly alter human hair follicle functions: anagen prolongation and stimulation of both hair matrix keratinocyte proliferation and hair pigmentation.
Thyroid hormones directly affect human hair follicles, affecting hair growth, keratinocyte proliferation, and pigmentation.
In Vitro Study
Rigorous Journal
Highly CitedImpaired Hair Growth and Wound Healing in Mice Lacking Thyroid Hormone Receptors
Thyroid hormone receptors play a crucial role in hair growth and skin homeostasis, suggesting potential targets for treating cutaneous pathologies.
Non-RCT
Animal StudyRigorous JournalImpact of Thyroid Dysfunction on Hair Disorders
Thyroid disorders have an underestimated prevalence and impact on hair loss, highlighting the need for more research to improve diagnosis and management of hair disorders.
Literature ReviewDIFFUSE THINNING OF HAIR IN IODIDE‐INDUCED HYPOTHYROIDISM
Stopping self-medication with iodide-containing powders can reverse symptoms and regrowth of hair, indicating drug-induced hypothyroidism.
Case ReportHuman female hair follicles are a direct, nonclassical target for thyroid-stimulating hormone.
Female hair follicles are direct targets for nonclassical thyroid-stimulating hormone bioregulation, potentially affecting hair loss and promoting hair growth.
In Vitro StudyHighly CitedAre you tired? Low Thyroid may be the Culprit: Part 1
Low thyroid hormone levels can cause low energy, weight gain, hair loss, and depression, but a proper diagnosis and treatment can help prevent these symptoms and improve overall health.
Thyroid hormone receptor beta1 is expressed in the human hair follicle.
Thyroid hormone receptor beta1 is the predominant form expressed in human hair follicles, and free T3 significantly enhances hair survival in vitro.
In Vitro StudyThyroid Functions in Patients with Diffuse Hair Loss
Abnormal thyroid functions are significant in a significant number of diffuse hair loss cases, making it mandatory to investigate them in all cases of diffuse hair loss in adult women.
Thyroidism Effect on Alopecia Patients In Pakistan
Thyroxin tablets and hair fin tabs can reduce TSH levels and promote hair growth in alopecia patients.
Thyroid Disease in Alopecia Areata, Lichen Planopilaris, and Frontal Fibrosing Alopecia—A Case Control Study of 144 Patients
Thyroid dysfunction is not a significant predictor of alopecia in this study, with rates higher than the U.S. population but no significant differences compared to a control group.
Observational Study