What to expect from your Blood Test
What to Know Before Your Appointment
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Stay Hydrated
Fasting Requirements (8–12 Hours)
For the most accurate results, we recommend fasting for 8–12 hours before your test — water only during this time.
Fasting helps ensure reliable results for:
- Heart health
- Cardiovascular risk
- Diabetes markers
- Iron levels
- Testosterone levels
Please avoid prolonged fasting, as it may affect your results or cause light‑headedness during your test.
Do Not Smoke
Avoid smoking for at least 30 minutes before your appointment.
Avoid Strenuous Exercise
Please refrain from intense physical activity for 48 hours prior, as exercise can alter certain blood markers.
General Supplementation
Unless prescribed by your doctor, pause supplements for 48 hours before your test.
If prescribed, please confirm with your doctor before stopping.
Biotin (Vitamin B7)
Biotin can interfere with many laboratory tests and distort results.
Unless prescribed, stop biotin for 48 hours before testing; otherwise, consult your doctor first.
Appointment Timing
Plan for Around 30 Minutes
While the blood draw itself typically takes 15 minutes, we recommend allowing 30 minutes for check‑in and any short waiting time.
At the London General Practice detailed blood tests are also carried out as part of our range of comprehensive health screens.
Enquire now
Web Enquiry LGP: Web Enquiry
Phone: 020 7935 1000
Email: info@thelondongeneralpractice.com
The London General Practice offers a number of screening services. To find out more about all screening services available at The London General Practice click below.
