Reference information for patients attending The Health Suite
Blood tests are a valuable tool for understanding health, monitoring conditions, and guiding treatment. Some blood markers are stable throughout the day, while others are influenced by timing, fasting, medications, supplements, hormone therapy, exercise, sleep, illness, and stress.
This page provides general preparation information for all blood tests offered at The Health Suite, with additional context for tests that include hormones, glucose, or insulin, as these markers are more sensitive to external influences.
Not every point below will apply to every test or every patient, but we recommend reading this page before your appointment.
Timing of Blood Tests
Most blood tests can be taken at any time during the day.
Some blood markers are known to show normal physiological variation across the day (diurnal variation). For this reason, many laboratories and clinical frameworks use morning sampling (commonly around 8–10 am) as a standardised reference point, particularly for baseline assessment or comparison over time.
Blood tests taken later in the day are still valid. The time of sample collection is recorded and taken into account during clinical interpretation, especially when reviewing trends or repeat testing.
For follow-up tests, having blood taken at a similar time of day can improve comparability.
Blood Tests Commonly Optimised for Morning Testing
Blood tests in this category are usually recommended to be taken at 8-10 am
The following blood markers are commonly referenced to morning sampling in clinical and laboratory medicine. This is for standardisation and comparability, not because results taken later in the day are invalid.
- Total testosterone
- Free testosterone
- Calculated free testosterone
- Bioavailable testosterone
- Androstenedione
- DHEA-S
- Sex Hormone Binding Globulin (SHBG)
- Luteinising hormone (LH)
- Follicle-stimulating hormone (FSH)
- Prolactin
- Growth hormone
- IGF-1
- Cortisol (serum)
- ACTH
- Aldosterone
- Plasma renin activity / Direct renin
- Fasting glucose
- Fasting insulin
- HOMA-IR (calculated)
- C-peptide (fasting context)
- Proinsulin
Fasting
Some blood tests require fasting for the most reliable results. If your panel includes glucose, testosterone, insulin, or insulin-resistance markers:
- Fast for 8–12 hours
- Water is allowed
- Avoid food, sugary drinks, and milk (including in tea or coffee)
Fasting does not require an early-morning appointment. Blood tests can be performed at any point during clinic hours once the fasting period is complete.
Lipid (Cholesterol) Tests
If your panel includes cholesterol or lipid markers:
- Avoid alcohol for 24 hours before testing
- Avoid unusually large or high-fat meals the day before
- Attend well hydrated
Lipid levels can fluctuate day-to-day and are interpreted in clinical context, rather than as a single isolated result.
Hormone Replacement Therapy (HRT) & Testosterone Therapy
Please do not stop prescribed hormone treatments unless specifically advised.
If your blood test includes hormone markers, results are interpreted in relation to treatment type and timing.
Topical hormones (gels, creams, sprays, patches)
- Blood results are considered in relation to when the last dose was applied
- Many people have blood taken before the next scheduled dose
- Treatment can be resumed after the blood test
If you apply hormone treatments to your arms, blood should be taken from the opposite arm.
If this is not possible, please inform the clinician at the time of your appointment.
Injectable hormones (e.g. testosterone)
- Results are interpreted relative to the timing of the last injection
- Please ensure the clinic knows:
- Medication
- Dose
- Frequency
- Date of last injection
Medications & Supplements
Please ensure the clinic has an up-to-date list of all medications and supplements you are taking.
Some supplements can interfere with laboratory assays, including:
- Biotin (commonly found in hair, skin and nail supplements)
- Non-prescribed hormone products
- Testosterone boosters or DHEA (if not prescribed)
Where possible, these are often paused 48–72 hours before testing, unless advised otherwise.
Continue all prescribed medications unless you have been told not to.
Exercise, Sleep & Lifestyle
In the 24 hours before testing, where possible:
- Avoid strenuous or unaccustomed exercise
- Avoid sauna, steam rooms, or cold immersion
- Aim for a normal night’s sleep
- Avoid major changes to your usual diet (unless fasting is required)
These factors can influence hormones, glucose regulation, and inflammatory markers.
Illness, Infection & Stress
Acute illness, infection, or significant physical or emotional stress can temporarily affect some blood results.
If you are unwell on the day of your appointment, please inform the clinic so this can be considered during interpretation.
How Results Are Interpreted
Blood test results are not interpreted in isolation.
Clinicians consider:
- Symptoms
- Medical history
- Medications and supplements
- Hormone therapy use
- Fasting status
- Timing of the blood test
If preparation or timing was not ideal, this does not automatically invalidate results, but it may influence interpretation or whether repeat testing is recommended.
Results Review & Follow-Up
Blood tests provide clinical data only. Interpretation and medical advice are separate clinical services.
- A GP or clinician review appointment is not included with blood testing unless this has been specifically selected and booked at the time of booking.
- Results are shared once received from the laboratory, usually electronically.
Abnormal Results
- If results show abnormal or clinically relevant findings, you may be advised to book a GP or clinician appointment for appropriate review and discussion.
- This advice will be provided alongside your results where applicable.
Urgent or Significantly Abnormal Results
- If results indicate a potentially serious or urgent clinical concern, a doctor may attempt to contact you directly.
- This contact may occur outside standard clinic hours, including evenings or weekends, where clinically appropriate, in the interest of patient safety.
Important
- Blood test results should always be interpreted in clinical context, alongside symptoms and medical history.
- Written or automated result notifications do not replace a medical consultation.
- If you have concerns about your results, or wish to discuss them in detail, please book a GP or clinician review appointment.
Common Q&A about Preparing for Your Blood Test at The Health Suite
Our FAQ section is designed to address common questions you may have, from how our treatments work to what you can expect during and after your session.
Our team is always available to provide additional support if you need more personalised guidance, ensuring that you feel informed and confident every step of the way.
Only some tests require fasting, particularly glucose and insulin-related tests. If unsure, contact the clinic.
Yes. Most blood tests can be taken at any time during the day. Timing is recorded and considered during interpretation.
Some hormones and metabolic markers naturally vary throughout the day. Morning sampling is commonly used as a reference point for comparison.
No. Prescribed hormone treatments should not be stopped unless advised. Timing and context are more important.
Yes, if you apply hormone gels or creams to your arms. Blood should ideally be taken from the opposite arm.
Yes. Supplements such as biotin and non-prescribed hormone products can interfere with some tests.
Yes. Strenuous exercise can temporarily affect hormones, glucose, and inflammatory markers.
Your results are still valid. Preparation and timing are taken into account during interpretation.
Yes. Cholesterol and lipid levels can vary depending on diet, alcohol intake, and hydration.
Please contact The Health Suite team before your appointment — we’re happy to advise.