In my previous articles, we’ve talked about why “normal” doesn’t always mean “optimal” and explored some of the bloodwork markers I discuss most often with clients. But there’s another important piece of the puzzle that often gets overlooked—how you prepare for your bloodwork.
Believe it or not, what you do before your blood is drawn can influence certain results. While not every test requires special preparation, taking a few simple steps can help ensure your results are as accurate and meaningful as possible.
Should You Fast?
Not every blood test requires fasting, so it’s important to follow the instructions provided by your healthcare provider. However, if your bloodwork includes glucose, insulin, cholesterol, or triglycerides, fasting is often recommended.
Generally, this means avoiding food for 8–12 hours before your blood draw while continuing to drink plain water. Staying hydrated can actually make it easier to draw your blood and may help improve the quality of the sample.
Morning or Afternoon?
Whenever possible, I encourage clients to have bloodwork done in the morning.
Many hormones, including cortisol and testosterone, naturally fluctuate throughout the day. Morning collections often provide the most consistent results and allow for easier comparison if you’re repeating labs in the future.
Consistency is important. If you typically have your annual bloodwork at 8:00 a.m., try to schedule future testing around the same time whenever possible.
What About Supplements?
This is one of the questions I hear most often.
Some supplements—particularly biotin (commonly found in hair, skin, and nail products)—can interfere with certain laboratory tests, especially thyroid testing. Depending on the tests being performed, your healthcare provider may recommend temporarily stopping specific supplements before your blood draw.
Unless you’ve been instructed otherwise, continue taking prescription medications exactly as directed. If you’re unsure about a medication or supplement, it’s always best to ask your healthcare provider before making any changes.
Exercise Can Influence Results
A strenuous workout the evening before or the morning of your bloodwork may temporarily affect certain markers, including blood sugar, inflammatory markers, muscle enzymes, and hydration status.
If your goal is to establish a baseline, consider saving the intense workout until after your appointment.
Keep Copies of Your Results
One of the best habits you can develop is requesting a copy of your bloodwork each year.
Instead of looking at a single snapshot, you and your healthcare team can begin to identify trends over time. A marker that has slowly changed over several years may provide more valuable insight than one isolated result.
Our health isn’t static. Looking at patterns helps us better understand where we’ve been—and where we’re headed.
Bloodwork Is One Piece of the Puzzle
Bloodwork provides an incredible amount of information, but it doesn’t tell the entire story.
Your symptoms, nutrition, sleep, stress levels, movement, medications, health history, and lifestyle all contribute to your overall health. That’s why I never look at lab results in isolation. Each piece of information helps us better understand how the body is functioning and where there may be opportunities to provide additional support.
The goal isn’t to chase perfect lab numbers. The goal is to better understand your body so you can make informed decisions that support your health today and in the years to come.
Bloodwork is often where the conversation begins—but sometimes it’s not where the story ends.
In my next article, we’ll explore what happens when bloodwork doesn’t provide all the answers. We’ll discuss how bloodwork, gut health, and hormone testing each offer different pieces of the puzzle—and why looking at the whole picture can provide valuable insight into your overall health and wellness.
Your Partner in Health,
Reg
