How is the DUTCH test different from a standard hormone blood test?

Serum tests capture a single moment in time and measure only total hormone levels, including protein-bound forms your tissues cannot use. The DUTCH test collects urine samples over 24 hours, providing a daily average. It measures metabolites rather than parent hormones, revealing how your body processes and clears hormones. This is where the clinical story lives.

Do I need to stop any medications before testing?

Certain medications affect panel results significantly, particularly hormonal contraceptives, hormone replacement therapies, and some thyroid medications. Your ND will advise on the protocol for each before your draw. In some cases, we test while on medication and interpret results accordingly.

What is EndoAxis and how is it different from a doctor just reading the numbers?

EndoAxis is a clinical hormone-analytics platform co-founded by Dr. Citrin and built for hormonal complexity. It maps your hormonal data against a database of hundreds of documented patterns and weighs the ratios between metabolites rather than single values against a reference range. The Citrin Longevity team reads those patterns in full clinical context, surfacing correlations a standard review can miss, particularly around estrogen metabolism. A doctor decides what it means for your protocol.

I have already had labs done by my regular doctor. Can you use those?

You can bring prior labs and we will review them. In most cases, we run our own panels because the markers measured, the reference ranges used, and the interpretation approach differ significantly. Prior results are useful as historical context, not as a substitute for the comprehensive diagnostic baseline we build.

Do you test ApoB and Lp(a), and why do they matter more than standard cholesterol?

Yes. ApoB counts the actual number of artery-clogging particles, which is studied as a stronger predictor of cardiovascular risk than LDL alone. Lp(a) is a mostly genetic marker associated with higher heart risk that a standard lipid panel misses. Both are part of the comprehensive panel we run for Los Angeles patients.

If Lp(a) is genetic, do I need to retest it every time?

Lp(a) is largely set by your genes and changes very little over your life, so it usually only needs to be measured once. If your first result is elevated, the Citrin Longevity team uses that number to shape your long-term cardiovascular plan. Most other markers, like ApoB and inflammation, are tracked on a regular schedule instead.

Why test fasting insulin and HbA1c instead of just blood sugar?

A single glucose reading can look fine for years while insulin quietly climbs. Fasting insulin and HbA1c together are studied for catching early insulin resistance, sometimes long before standard glucose shifts. We include both so the picture reflects how your metabolism is trending, not just one moment.

What does hs-CRP tell you, and is it part of the panel?

hs-CRP is a marker of low-grade, ongoing inflammation that is associated with cardiovascular and metabolic risk. It is included in our comprehensive panel. The Citrin Longevity team reads it next to your other markers, since inflammation rarely shows up alone and usually points to something worth addressing at the source.

What is the difference between optimal ranges and the normal ranges on a regular lab report?

Standard reference ranges are built from a general population that includes many people who are not metabolically healthy, so falling inside them only means you are not clearly sick. Optimal ranges reflect where markers sit in healthier people. We interpret your results against optimal targets, then a doctor decides what each number means in your context.

How should I prepare for the blood draw, and can I have coffee first?

Most markers are read best after an 8 to 12 hour fast with plain water only, so no coffee, juice, or sweeteners beforehand. We generally suggest a morning draw and avoiding alcohol and hard workouts the day before. Your ND will tell you which supplements, including biotin, to pause and which medications to continue.

How often should I retest after we start a protocol?

We rerun the panels every 90 days so we can see whether your protocol is actually moving the markers we are targeting. Faster-changing markers like insulin and inflammation often shift within a few months. Once your numbers are stable, retesting can space out, and your biometric app keeps the trends in one place.

Do I need a doctor to order these labs, or can I just buy a panel myself?

You can buy some direct-to-consumer panels without a doctor, but the value sits in interpretation, not the raw numbers. Citrin Longevity is a doctor-led practice in West Hollywood, so a doctor orders the right tests for you and reads them in full clinical context. That is the difference between a printout and a plan.

How is this different from Function Health or other large at-home panels?

Large direct-to-consumer panels give you many markers and an app, then often leave the interpretation to you. Our work is doctor-led from the start: the Citrin Longevity team reads your panel and DUTCH results together, against your history, and builds a specific protocol. Many Los Angeles patients bring us outside panels precisely so a doctor can act on them.

Are IgG food sensitivity tests accurate, and how do you use them?

IgG food testing is debated, and a positive result often reflects exposure rather than a true problem. We treat it as one clue, not a verdict, and never as a stand-alone diagnosis. The Citrin Longevity team weighs it against your symptoms, gut markers, and history before suggesting any dietary change.

How long do results take, and can I track my markers over time?

Full results, including the DUTCH panel, are typically ready and reviewed with you within about two weeks of collection. Your markers are stored in a proprietary biometric app so you can follow trends across each 90-day retest. That longitudinal view shows whether ApoB, insulin, and inflammation are actually improving, not just a single snapshot.