1,25-dihydroxyvitamin D (calcitriol)
This test measures 1,25-dihydroxyvitamin D, the biologically active form of vitamin D. It is used to investigate calcium imbalance, kidney disease and...
The Pituitary Function Profile evaluates hormones that control major endocrine glands. It helps assess pituitary health, hormone balance, and systemic regulation.
Turnaround time
8 days
Biomarkers count
6
Professional phlebotomist comes to you
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SelectedThe Pituitary Function Profile is a comprehensive blood test panel that assesses hormones produced or regulated by the pituitary gland, often referred to as the “master gland” of the endocrine system. It plays a central role in controlling thyroid function, reproduction, growth, stress response, and metabolism.
This profile includes:
Thyroid Stimulating Hormone (TSH)
Follicular Stimulating Hormone (FSH)
Luteinising Hormone (LH)
Prolactin
Growth Hormone (GH)
Cortisol
Together, these markers provide a broad overview of pituitary activity and its downstream effects on other endocrine organs such as the thyroid, adrenal glands, ovaries, and testes.
Pituitary dysfunction can lead to widespread hormonal imbalance because the pituitary regulates multiple glands simultaneously. Symptoms are often vague, overlapping, and easily misattributed to stress or lifestyle factors.
This profile is particularly useful when investigating unexplained fatigue, fertility issues, menstrual irregularities, sexual dysfunction, abnormal growth patterns, or suspected endocrine disorders.
You may benefit from this test if you experience:
Persistent fatigue or weakness
Unexplained weight changes
Irregular menstrual cycles or infertility
Low libido or sexual dysfunction
Headaches or visual disturbances
Milk discharge from breasts (galactorrhoea)
Abnormal thyroid or cortisol results
Suspected pituitary or hormonal disorders
Assesses overall pituitary gland activity
Provides insight into the central regulator of the endocrine system.
Evaluates thyroid regulation
TSH helps determine whether thyroid issues originate from the pituitary.
Supports fertility and reproductive assessment
FSH and LH are essential for ovulation, sperm production, and sex hormone balance.
Investigates prolactin-related symptoms
Elevated prolactin can affect fertility, libido, and menstrual cycles.
Assesses growth hormone regulation
Supports investigation of abnormal growth, muscle mass, or metabolic issues.
Evaluates stress and adrenal response
Cortisol reflects pituitary–adrenal axis function.
Supports diagnosis of pituitary disorders
Useful in suspected pituitary adenomas or hypopituitarism.
Guides targeted follow-up testing
Helps determine which endocrine pathways require further investigation.
Choose your nearest UK clinic
Attend your appointment
A qualified clinician or phlebotomist collects your blood sample
Sample is sent to the laboratory for analysis
A qualified phlebotomist visits your home or hotel
Blood sample collected in a comfortable, familiar setting
No clinic visit or travel required
Both services are available UK-wide.
Low levels of one or more pituitary-related hormones may indicate reduced pituitary output (hypopituitarism) or impaired signalling to target glands. This can result in reduced thyroid activity, low sex hormone production, adrenal insufficiency, or growth hormone deficiency.
Symptoms may include fatigue, infertility, low libido, weight gain, and reduced stress tolerance.
UK reference interpretation:
Low: Below laboratory-specific reference range
Normal results suggest appropriate pituitary regulation of thyroid, adrenal, reproductive, and growth-related functions. This indicates balanced endocrine signalling and effective hormonal feedback mechanisms.
Symptoms may still exist if target glands are resistant or if hormonal fluctuations occur.
UK reference interpretation:
Normal: Within laboratory-specific reference ranges
Elevated pituitary hormone levels may reflect excessive stimulation of target glands or compensatory response to gland underactivity. In some cases, high levels may suggest pituitary adenomas or endocrine feedback disruption.
Further clinical evaluation may be required depending on which hormones are elevated.
UK reference interpretation:
High: Above laboratory-specific reference range
Simple steps to get your results
Choose your test online and book in seconds. Select your preferred clinic location or home visit option.
Attend one of our UK or London clinics, arrange a home nurse visit, or use a finger-prick kit where available.
Your sample is analysed by accredited UK laboratories, with secure results delivered directly to you.
Take control of your health with London Blood Tests
WhatsApp UsFollow these guidelines for accurate results
Where possible, attend your blood test between 7am and 12pm. Please wait until any short-term illness or infection has fully resolved before testing. Avoid intense exercise for 24–48 hours beforehand, as this can affect certain markers.
Fasting is not always required, but some tests may recommend it. If fasting is advised, avoid food for 8–12 hours before your appointment and drink water only. Stay well hydrated, as this helps with sample collection and accuracy.
Continue prescribed medications unless advised otherwise by your clinician. Avoid vitamin, mineral, or biotin supplements for at least 24–48 hours before your test, as these can interfere with results. If you are unsure about any medication or supplement, please let us know before your appointment.
For hormone-related tests, timing within your menstrual cycle may be important. If relevant, follow any specific guidance provided on your test page.
If you have any questions or special circumstances, our team is happy to advise before your appointment.
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