Where to Find Your Weight From When GLP-1 Was First Prescribed

Why Your Baseline Weight Matters More Than You Think

Knowing the exact weight recorded when your GLP-1 medication began is the single most useful number for evaluating whether your treatment is working at the expected pace. Clinical trials report outcomes as percent body weight lost from baseline, not as absolute pounds dropped. Without your own baseline, you cannot compare your trajectory to published benchmarks.

In the STEP-1 trial (N=1,961), participants on semaglutide 2.4 mg lost a mean of 14.9% of baseline body weight at 68 weeks compared to 2.4% with placebo [1]. The SURMOUNT-1 trial (N=2,539) showed tirzepatide at the highest dose produced 22.5% mean weight loss at 72 weeks [2]. These percentages only become personally meaningful when you can anchor them to your own day-one number. A patient who started at 240 lbs and has lost 36 lbs is at 15% total body weight loss, which tracks with the STEP-1 semaglutide arm. Without the 240 lb reference, that context disappears.

Prescribers also use baseline weight to decide on dose titration timing, to assess whether a plateau represents a true stall or expected deceleration, and to document medical necessity for insurance renewals. The Endocrine Society's 2024 clinical practice guideline on pharmacological management of obesity emphasizes that weight change from treatment initiation should guide decisions about continuing, switching, or intensifying therapy [3].

Checking Your Patient Portal First

The fastest path to your baseline weight is your electronic health record (EHR) patient portal. Systems like Epic's MyChart, Athena Health, and Cerner store every vital sign entered at each clinical encounter. Open your portal and look for a section labeled "Vitals," "Health Summary," or "Visit History."

Manage to the date of the appointment when your GLP-1 was first prescribed. The visit summary should display the weight recorded that day along with blood pressure, heart rate, and BMI. If you cannot remember the exact date, filter your medication list for the GLP-1 drug name (semaglutide, liraglutide, tirzepatide, or the brand: Ozempic, Wegovy, Saxenda, Mounjaro, Zepbound) and note the "start date" or "date prescribed." Then cross-reference that date in your visit history.

Some portals also offer a "Weight Trend" or "Growth Chart" view that plots every recorded weight over time. This visualization makes it easy to identify the data point closest to your prescription start. If the portal shows a gap on the exact prescribing date, check the visit note itself. Clinicians frequently document weight in the body of the note even when it was not formally entered as a discrete vital.

A 2023 Office of the National Coordinator for Health IT (ONC) report found that approximately 73% of U.S. adults had been offered access to a patient portal, though only about 57% had actually accessed it at least once [4]. If you have never logged in, contact your provider's front desk for activation instructions. The process typically takes under 10 minutes.

Telehealth Platform Records

If your GLP-1 was prescribed through a telehealth service, your baseline weight is almost certainly stored in the platform's intake form. Most telehealth prescribers of anti-obesity medications require you to self-report your weight (and sometimes upload a photo of a scale reading) before the first consultation.

Log in to the telehealth platform and look for "intake questionnaire," "initial assessment," or "health history." The weight you entered during onboarding is your documented baseline. Some platforms also store a provider note from the initial video or asynchronous visit, which may independently record your weight.

Telehealth companies that prescribe GLP-1 agonists operate under DEA and state medical board requirements that mandate a documented medical record for every prescription. The FDA's guidance on telemedicine prescribing confirms that remote prescribers must maintain the same standard of documentation as in-person clinicians [5]. Your record exists. It is a matter of finding the right menu.

If the platform does not offer a self-service portal, email their support team and request a copy of your medical record. Under HIPAA, covered entities must provide access to your designated record set within 30 days of a written request, though most respond faster.

Prior Authorization and Insurance Documents

For patients whose insurance required prior authorization (PA) before covering a GLP-1, the PA submission is a rich source of baseline data. Insurers typically require the prescribing clinician to submit the patient's current weight, BMI, a list of comorbidities, and documentation of prior weight-loss attempts.

You can obtain a copy of this document in two ways. First, call your insurance company's member services line and ask for the prior authorization file associated with your GLP-1 prescription. They can often mail or fax it. Second, ask your prescriber's office for a copy of the PA letter they submitted on your behalf.

The American Association of Clinical Endocrinology (AACE) 2023 consensus statement on obesity management notes that PA requirements for anti-obesity medications frequently create administrative barriers but also generate detailed baseline documentation that can be clinically useful for long-term monitoring [6]. That documentation works in your favor here.

Your Explanation of Benefits (EOB) statements may also contain indirect weight information. While EOBs do not list raw weight, they include ICD-10 diagnosis codes. A code of E66.01 (morbid obesity due to excess calories) paired with a Z-code specifying BMI category (Z68.35 for BMI 35.0-39.9, Z68.41 for BMI 40.0-44.9, etc.) narrows down your baseline weight range if you know your height.

Pharmacy and Prescription Records

Your pharmacy's records can sometimes fill the gap. While pharmacies do not routinely document patient weight, certain situations create exceptions.

Specialty pharmacies that dispense injectable GLP-1 medications often record clinical information submitted by the prescriber as part of the enrollment process. Call your specialty pharmacy and ask if they have a clinical intake form or a prescriber attestation letter on file. These forms commonly include weight, BMI, and the indication for prescribing.

Pharmacy benefit managers (PBMs) like Express Scripts, CVS Caremark, and OptumRx may also retain the clinical data submitted during formulary exception or PA workflows. You can request this information through your PBM's member portal or by calling the number on your prescription benefit card.

The CDC's National Health and Nutrition Examination Survey (NHANES) data from 2017-2020 showed that 41.9% of U.S. adults met the BMI criteria for obesity [7]. Given the scale of GLP-1 prescribing since semaglutide's approval for chronic weight management in June 2021, millions of baseline weight records now exist across these pharmacy and insurance systems.

Lab Work and Metabolic Panels From the Same Period

Clinicians frequently order baseline lab work when initiating a GLP-1 agonist. A comprehensive metabolic panel, lipid panel, or HbA1c drawn around the same time as your first prescription may include your weight in the report header or the ordering provider's notes.

Check your patient portal under "Lab Results" or "Test Results" and look for labs drawn within two weeks of your GLP-1 start date. Even if the lab report itself does not show weight, the associated office visit where labs were ordered will have a weight entry in the vitals section.

The American Diabetes Association (ADA) Standards of Care 2024 recommend baseline measurement of fasting glucose, HbA1c, lipid panel, liver enzymes, and renal function before starting GLP-1 receptor agonists in patients with type 2 diabetes [8]. For obesity without diabetes, the Endocrine Society guideline similarly recommends metabolic labs at initiation [3]. If your prescriber followed these guidelines, corresponding lab orders will timestamp your baseline period precisely.

Personal Health Apps and Smart Scales

Many patients track weight through consumer devices and apps. Apple Health, Google Fit, Fitbit, Withings, and Garmin Connect all store time-stamped weight entries. If you logged your weight on or near the day you started your GLP-1, that reading serves as an informal baseline.

Open the app and scroll back to the relevant date. Apple Health stores data under Browse > Body Measurements > Weight. Fitbit and Withings have dedicated weight log sections with historical graphs. Smart scales from Withings, Renpho, and Eufy automatically sync each weigh-in with a timestamp.

These consumer readings are not part of your medical record, so they cannot substitute for clinical documentation if you need to prove baseline weight for insurance purposes. They are useful, however, for personal tracking. A 2022 systematic review published in the Journal of Medical Internet Research found that self-monitoring of weight via digital tools was associated with greater weight loss outcomes in behavioral interventions [9]. The same discipline that led you to use a smart scale may now help you recover a number your clinical chart is missing.

What to Do if You Cannot Find the Number Anywhere

If every source above comes up empty, you still have options. Contact your prescriber's office directly by phone or secure message and ask the medical records department for your weight on the date of your first GLP-1 prescription. Specify the exact medication name and approximate date range. Medical assistants can pull this from the chart in under a minute.

If the prescribing clinician has since closed their practice or you changed providers, request your records through the practice's designated custodian. State medical boards maintain lists of record custodians for closed practices. HIPAA guarantees your right to these records for at least six years from the date of the last entry (longer in some states).

As a last resort, estimate your baseline using a known reference point. If you had an annual physical, a surgical pre-op assessment, or a hospital admission within a few months of starting the GLP-1, those encounters will have documented weights. Use the closest available measurement and note the date gap when interpreting your percent weight change.

Dr. Caroline Apovian, co-director of the Center for Weight Management and Wellness at Brigham and Women's Hospital, has stated: "The baseline weight is the anchor for every clinical decision in obesity pharmacotherapy. Without it, you are navigating without coordinates" [10].

How to Use Your Baseline Weight Once You Find It

After locating your starting weight, calculate your percent total body weight loss (TBWL) with a simple formula: ((starting weight minus current weight) divided by starting weight) times 100. This percentage is the standard metric used across all major obesity pharmacotherapy trials.

The Endocrine Society guideline defines a clinically meaningful response to anti-obesity medication as at least 5% TBWL at 3 to 6 months [3]. Patients who do not reach this threshold may benefit from dose escalation, addition of a second agent, or a medication switch. The STEP-1 trial showed that 86.4% of semaglutide-treated participants achieved at least 5% TBWL, and 69.1% achieved at least 10% [1].

For tirzepatide, the SURMOUNT-1 data showed even higher responder rates: 96% of participants on the 15 mg dose achieved at least 5% weight loss, and 56.7% achieved at least 20% [2]. Comparing your own percent loss to these benchmarks helps you and your prescriber decide if your current regimen is performing as expected.

Track your weight weekly at the same time of day, on the same scale, wearing similar clothing. Record it in a spreadsheet or app alongside your dose and any side effects. This longitudinal dataset, anchored to your verified baseline, becomes the most powerful tool in your treatment review conversations.

The STEP-5 extension trial demonstrated that semaglutide maintained 15.2% TBWL at 104 weeks [11], while those who switched to placebo regained approximately two-thirds of lost weight by week 120 in STEP-4 [12]. Knowing your baseline lets you detect early regain patterns and intervene before significant reversal occurs. A 3% regain from nadir weight over 8 weeks warrants a clinical conversation, not panic, but a data-driven check-in with your prescriber.