Your Period & Your Bloodwork: What to Know Before Testing | Queen Creek, AZ



How Your Period Can Affect Blood Test Results

Your menstrual cycle causes natural shifts in hormone levels, red blood cell counts, and inflammatory markers. While many routine tests remain valid regardless of timing, others can be skewed depending on which phase of your cycle you’re in.



Hormones

If you're testing for reproductive hormones like estrogen, progesterone, FSH, or LH, the timing of your draw matters a lot. These hormones fluctuate daily, and providers often request testing on specific cycle days (like Day 3 or Day 21) to evaluate fertility or menstrual disorders.

Testing on the wrong day could lead to confusing or inconclusive results, and may require a retest.



Complete Blood Count (CBC) & Iron Levels

Menstruation causes blood loss, which can temporarily lower your hemoglobin, hematocrit, and ferritin levels. If you’re checking for anemia, it’s best to test a few days after your period ends for the most accurate picture of your iron stores.

That said, if you're feeling especially tired or lightheaded during your period, testing during menstruation may help uncover an underlying deficiency worth addressing.



Inflammatory Markers

CRP (C-reactive protein) and other inflammation-related markers can be slightly elevated during menstruation. This doesn’t always mean something is wrong, but it’s worth letting your provider know where you are in your cycle when reviewing results.



Which Tests to Avoid During Your Period

You don’t need to cancel every lab just because your period started, but here are a few tests that are better timed outside your menstrual phase:

❌Hormone Panels: Estrogen, progesterone, LH, FSH

❌Iron Studies: Ferritin, hemoglobin, hematocrit

❌CRP or Other Inflammatory Panels: To avoid false elevation

❌Thyroid Testing (sometimes): Some studies suggest TSH may slightly fluctuate, but results are usually still reliable

If your provider didn’t specify timing, it’s okay to ask whether your cycle might affect the results of your specific panel.

Which Tests Are Still Accurate During Your Period?

Thankfully, many standard blood tests aren’t impacted by your cycle and can be performed at any time:

✅CMP (Comprehensive Metabolic Panel) – Checks hydration, kidney, and liver function

✅Lipid Panel – Cholesterol, HDL, LDL, triglycerides

✅Vitamin D & B12 – Nutritional markers that remain stable

✅Glucose & A1C – Used for diabetes screening



✅Most Specialty Kits – Timing is usually flexible unless hormone-related

These tests are typically fine to complete regardless of where you are in your cycle.

Tips for Testing During Your Period

If you need to get tested while on your period, here are a few tips to help you feel more prepared:

⁍ Stay hydrated – Blood volume is a little lower during menstruation, so hydration helps make the draw easier.

⁍ Avoid high-intensity workouts – Strenuous activity can temporarily elevate some lab values.

⁍ Tell your provider – Let them know where you are in your cycle when reviewing your results.

⁍ Rest if you feel lightheaded – Some people feel more faint during their period, so allow time to recover after your draw.

Why Mobile Lab Work Is Ideal for Testing Around Your Cycle

One of the biggest benefits of using a mobile phlebotomy service near me is the flexibility and comfort it offers—especially during your period.

At OptiVena Mobile Phlebotomy, we bring the lab to your door. That means no long waits at the clinic, no sitting in crowded waiting rooms while you’re cramping, and no pressure to rush out the door when you’re not feeling your best.

☑︎ Our at home lab draw option allows you to:

☑︎ Rest in your own space during the draw

☑︎ Choose a day and time that aligns with your cycle

☑︎ Ask questions and receive personalized care from our experienced phlebotomists



☑︎ Enjoy peace of mind knowing your specimens are processed and delivered properly—even on weekends

Testing Should Work With Your Body, Not Against It

Your menstrual cycle is a natural rhythm—and your lab work should respect that. Whether you’re tracking hormone changes, checking for nutrient deficiencies, or managing a medical condition, knowing how your period affects your results gives you the power to plan better.

Need help timing your next test? Not sure if you should wait? Reach out to your provider or contact us—we’re happy to help you schedule your at home blood draw when it makes the most sense for your body.



OptiVena Mobile Phlebotomy proudly serves clients across the Phoenix metro, from Phoenix to Queen Creek and San Tan Valley to Buckeye. Wherever you are in the Phoenix valley, we provide at home blood draw service near you.