Concierge endocrine testing · London
Dynamic endocrine function tests, provocation and suppression testing for pituitary, adrenal and glucose disorders.
Dynamic function tests use provocation or suppression to expose subtle endocrine dysfunction that resting bloods miss. Common tests: short synacthen, insulin-tolerance, oral glucose tolerance, water deprivation, glucagon stimulation, dexamethasone suppression and TRH.
Why patients choose us
- 01
Consultant endocrinologist reporting
The person interpreting a dynamic test is the one who decides the diagnosis — we route you to a consultant endocrinologist, not a generalist.
- 02
Endocrine day-unit safety
Provocation testing needs trained nurses, rescue drugs and IV access on hand — every partner unit is set up for it.
- 03
Independent, and free
We are paid by no clinic, so the recommendation is impartial and costs you nothing.
Indicative pricing
What private dynamic function tests cost in London.
Indicative ranges across our partner endocrine day-units. Send the details and we quote firm figures across two or three options.
In short
A short synacthen test in our network: £350–£600, with the written report typically within a week.
| Test | Indicative range | Typical duration | Report turnaround |
|---|---|---|---|
| Short synacthen test (adrenal insufficiency) | £350–£600 | 90 min | Same-week |
| Oral glucose tolerance test (OGTT) | £200–£400 | 2.5 hr | Same-week |
| OGTT with GH suppression (acromegaly) | £450–£800 | 3 hr | 1 week |
| Insulin tolerance test (ITT, GH / ACTH) | £800–£1,400 | Half-day | 1 week |
| Water deprivation test (diabetes insipidus) | £900–£1,500 | Full day | 1 week |
| Low-dose dexamethasone suppression (Cushing’s screen) | £250–£450 | Overnight | 1 week |
| Glucagon stimulation test | £600–£1,000 | Half-day | 1 week |
| TRH stimulation test | £400–£700 | 90 min | 1 week |
Prices vary by clinic, whether the test needs consultant supervision (ITT), and whether the endocrine consultation is bundled in. We come back with a firm quote within one working day.
The problem
Resting bloods miss subtle endocrine disease.
Cortisol, growth hormone and ACTH swing hour to hour — a single resting sample often looks normal even when the underlying axis is failing. Dynamic tests provoke or suppress the axis to force the answer out.
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Unexplained fatigue and low sodium?
Adrenal insufficiency hides behind vague symptoms. A short synacthen test settles it in 60 minutes.
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Weight gain, bruising, thin skin?
A low-dose dexamethasone suppression test is the first-line screen for Cushing’s syndrome.
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Polyuria and thirst not explained by diabetes?
A water deprivation test separates cranial from nephrogenic diabetes insipidus.
The journey
From consultation to interpretation — what happens, in order.
One consultant endocrinologist from first message to written interpretation.
Phase 1 · Before the test
Consultation and preparation
Phase 2 · On the day
Endocrine day-unit
Phase 3 · After
Interpretation and plan
- 01
Before
Endocrine consultation
A consultant endocrinologist decides which dynamic test the clinical picture actually needs — and whether one is needed at all.
- 02
Before
Choose the test
Short synacthen, insulin-tolerance, OGTT, water deprivation, glucagon stimulation, low- or high-dose dexamethasone suppression, or TRH.
- 03
Before
Withhold interfering medications
Steroids, oestrogens, thyroxine and psychotropics can all skew the result — we write out exactly what to hold and for how long.
- 04
On the day
Fasting or supervised timing
Most tests are early morning and fasted. You arrive, the cannula goes in, baseline bloods are drawn.
- 05
On the day
Serial blood or urine sampling
Provocation or suppression agent given, then timed samples at defined intervals — a nurse is with you throughout.
- 06
On the day
Rescue treatment ready
IV glucose, hydrocortisone and monitoring are immediately to hand. The test is stopped at once if you feel unwell.
- 07
After
Written interpretation and plan
Consultant endocrinologist report with the diagnosis, the next investigation (pituitary MRI, adrenal CT) and the treatment pathway.
Typical end-to-end: 1–2 weeks. Urgent cases: within days.
What it shows
When a dynamic function test is the right test.
Dynamic tests answer specific endocrine questions — is the axis under- or over-active, and where in the chain is the lesion. These are the presentations we see most.
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Adrenal insufficiency
Short synacthen test — the reference test for primary and secondary adrenal failure.
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GH / ACTH deficiency
Insulin tolerance test remains the gold standard for combined pituitary reserve.
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Diabetes and IGT
Oral glucose tolerance test — diagnoses type 2 diabetes and impaired glucose tolerance.
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Diabetes insipidus
Water deprivation test with desmopressin distinguishes cranial from nephrogenic DI.
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Cushing’s syndrome
Low-dose dexamethasone suppression — the first-line screen for cortisol excess.
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Acromegaly
OGTT with paired GH — failure to suppress GH below 1 µg/L confirms the diagnosis.
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TRH stimulation
Rarely used now, but still valuable for equivocal pituitary–thyroid axis puzzles.
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Red flag: severe hypoglycaemia during ITT — immediate IV glucose and stop test
Any confusion, seizure or loss of consciousness during an ITT triggers immediate IV glucose and abandonment of the test.
Test types
Not all dynamic function tests are the same.
What each option on your endocrine referral is actually for.
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Short synacthen test
250 µg synthetic ACTH IV; cortisol measured at 0, 30 and 60 minutes. The reference test for adrenal insufficiency.
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Insulin tolerance test (ITT)
IV insulin induces hypoglycaemia; GH and cortisol responses probe the pituitary–adrenal axis. Consultant-supervised only.
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Oral glucose tolerance test
75 g oral glucose; plasma glucose at 0 and 120 min. Diagnostic for diabetes, IGT and — with GH — acromegaly.
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Water deprivation test
Supervised fluid restriction with paired plasma and urine osmolality, followed by desmopressin challenge.
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Dexamethasone suppression
Low-dose overnight (Cushing’s screen) or high-dose (differentiating pituitary from ectopic ACTH).
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Glucagon stimulation test
Safer alternative to ITT for GH and cortisol reserve — useful when insulin is contraindicated.
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TRH stimulation
IV TRH with paired TSH samples — occasionally used for atypical central hypothyroidism.
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Combined pituitary function test
Triple bolus (insulin, TRH, GnRH) assessing all anterior pituitary axes in one supervised morning.
Treatment and next steps
After a positive dynamic test, we route you on.
A dynamic test is a decision point, not an end point. The report includes the concrete next step — imaging, MDT review or the start of treatment.
Onward pathway
Every partner unit has the imaging and MDT route ready.
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Hormone replacement per deficit (hydrocortisone, thyroxine, sex steroids, GH)
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Cushing’s pathway — including petrosal sinus sampling where source localisation is unclear
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Pituitary MRI for confirmed pituitary hormone excess or deficiency
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Adrenal CT or MRI for cortisol- or aldosterone-secreting lesions
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Diabetes education and treatment initiation after a diagnostic OGTT
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Desmopressin for confirmed cranial diabetes insipidus
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Multi-disciplinary team review for pituitary, adrenal or thyroid tumours
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Follow-up dynamic testing to confirm treatment response
Safety and red flags
Safe when done properly — and only then.
Dynamic testing is safe when it is done in an endocrine day-unit with consultant supervision and rescue drugs on hand. The specific red flags below govern which tests can proceed and when they must stop.
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Test-specific protocols
Every dynamic test has its own timing, dose and safety window — the protocol is confirmed with you in writing before the day.
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Rescue medications ready
IV glucose, hydrocortisone and antiemetics are drawn up and to hand for every ITT and water deprivation test.
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Consultant supervision for ITT
The insulin tolerance test is only performed with a consultant endocrinologist physically present.
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Fasted from midnight
Most tests need an overnight fast; you can drink water. We tell you exactly which regular medications to take.
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Interfering medications withheld
Oral steroids, oestrogens, thyroxine and some antidepressants must be paused — the letter sets out timing.
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Pregnancy caveat
Insulin tolerance and water deprivation tests are avoided in pregnancy — safer alternatives are chosen.
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Phaeochromocytoma exclusion first
Suspected phaeochromocytoma is excluded biochemically before any provocation test that could precipitate a crisis.
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Bring a companion
You should not drive home after an ITT or water deprivation test — bring someone who can escort you.
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Baseline hormones and imaging
Dynamic tests are interpreted alongside resting bloods and any relevant pituitary or adrenal imaging.
Red flags — dynamic testing
- Severe hypoglycaemia during ITT
- Adrenal crisis
- Diabetic ketoacidosis
- Hyponatraemia post-desmopressin
- Cortisol response failure
- Suspected phaeochromocytoma
- Pituitary apoplexy
- Pregnancy
- Undiagnosed pituitary macroadenoma
Reading your report
A dynamic function report can look dense. It isn’t.
Whatever the test, the report keeps to the same four parts.
A quiet reminder
The report is written for your doctor, not for you — and that’s normal.
If you would like us to talk you through it before your follow-up, just ask.
- 01 Header
Indication and baseline hormones
Your details, the reason for the test, and the resting endocrine bloods that frame interpretation.
- 02 Protocol
Agent, dose and sampling schedule
Which provocation or suppression agent, the dose, and the exact time-points at which samples were drawn.
- 03 Results
Timed cortisol, GH, glucose or osmolality
Sample-by-sample values with reference thresholds — normal, borderline or diagnostic.
- 04 Impression
The diagnosis and the next step
The consultant’s conclusion and the concrete next investigation or treatment — read this first.
Recognised by major UK insurers
Cover depends on your policy and clinic; we confirm with your insurer before booking.
Frequently asked
Everything we get asked about dynamic function tests.
Quick answers on cost, referrals, which test you actually need, and what happens on the day.
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What are dynamic endocrine function tests?
Dynamic function tests use a provocation or suppression stimulus — a hormone, a drug or fluid restriction — to expose subtle endocrine dysfunction that resting blood tests miss. They are the reference tests for adrenal insufficiency, pituitary reserve, Cushing’s syndrome, acromegaly and diabetes insipidus.
-
Which dynamic test do I actually need?
The endocrine consultation decides. Short synacthen for suspected adrenal insufficiency, ITT for pituitary reserve, OGTT for glucose disorders or acromegaly, water deprivation for diabetes insipidus, dexamethasone suppression for Cushing’s. The right test depends on the clinical picture and baseline bloods.
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How much do dynamic function tests cost privately?
A short synacthen test is typically £350–£600. An OGTT is £200–£400. An insulin tolerance test — because it needs consultant supervision — runs £800–£1,400. A water deprivation test is £900–£1,500. We confirm a firm figure within one working day.
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Do I need a referral?
Most clinics accept self-referral for OGTT and dexamethasone suppression. ITT and water deprivation testing usually need a formal endocrine referral — we arrange a fast-track private endocrinologist if you don’t have one.
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What happens during an insulin tolerance test?
IV insulin is given to drop your blood glucose below 2.2 mmol/L. Cortisol and GH are sampled through the hypoglycaemic response, then IV glucose reverses it. It is only done with a consultant present and IV glucose ready.
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When would I need a pituitary MRI after dynamic testing?
When the dynamic test confirms pituitary hormone deficiency or excess — Cushing’s, acromegaly, ACTH or GH deficiency — a dedicated pituitary MRI is the next step to identify or exclude an adenoma.
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Is a water deprivation test safe?
It is safe when done in an endocrine day-unit with hourly weighing, close observation and rescue desmopressin ready. It is not safe unsupervised — dangerous hypernatraemia can develop rapidly.
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In practice, in London
How dynamic function tests tends to unfold when you go private
With dynamic function tests, the London question is usually about report turnaround and the radiologist reading it — not whether the scan is available. Waiting lists on the NHS for dynamic function tests vary widely by borough and by how the GP letter reads. Privately in London, we can normally offer a slot inside the same week, sometimes within 48 hours if there’s a cancellation. The difference isn’t clinical quality — the consultants are frequently the same faces you’d see on the NHS — it’s the calendar.
In practice, a private dynamic function tests appointment in London means a named consultant, a proper hour in the room (or the equivalent on a video call), and a report you can actually read. Most of the imaging suites and endoscopy units we use sit within a mile of Harley Street or in Chelsea and Fulham, and turnaround on findings is measured in days, not weeks. For dynamic function tests specifically, the difference between a routine report and a sub-speciality read is where private care earns its keep.
Honesty about expectations is part of the job. A private dynamic function tests appointment in London won’t change the underlying medicine — the guidelines, the consultants, and the equipment are largely the same as on the NHS. What it changes is speed, continuity, and the amount of time you get to actually talk through the findings. Everyone we route to is GMC-registered and works within CQC-regulated facilities.
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