Which Tests Are Needed Before Starting GLP-1 Therapy?
Most people in India are handed a GLP-1 pen after a single conversation about weight — no baseline bloods, no history taken, no plan for what happens next. A proper baseline is not a formality. It decides whether the medicine is appropriate for you at all, which starting approach is safer, and how anyone will later know whether it is working. Dr. Manuj Sondhi (MRCP, UK · MD · DNB), Consultant Physician & Diabetologist, sets out the assessment done before starting GLP-1 therapy at Nirvana Clinic, Greater Noida.
The short version: Before GLP-1 therapy, a doctor should take a full personal and family history, examine you, and arrange baseline blood tests — typically HbA1c and fasting glucose, kidney function, liver enzymes, a lipid profile, thyroid function, and a full blood count, with vitamin B12 and vitamin D where relevant. The history matters as much as the bloods: thyroid cancer in the family, past pancreatitis, gallstones, severe reflux or gastroparesis, pregnancy plans and eating patterns all change the decision. Anyone who prescribes a GLP-1 without any of this is not supervising your treatment.
Why a Baseline Matters More With GLP-1 Than With Most Medicines
GLP-1 receptor agonists (semaglutide, tirzepatide, liraglutide and the oral forms) are effective medicines. They are also medicines you may stay on for a long time, and they change several body systems at once — appetite, gastric emptying, blood sugar, and body composition. Three practical consequences follow.
1. Safety screening
A small number of people should not take these drugs at all, and some should start only with extra caution. Almost all of that is picked up by history and a handful of tests — not by looking at someone's weight.
2. Finding what's actually driving the weight
Untreated hypothyroidism, PCOS, uncontrolled diabetes, fatty liver, sleep apnoea and some prescribed medicines all contribute to weight gain. Treating those may be part of the answer — and skipping the tests means never finding them.
3. Proof it is working
Weight on a scale is a crude measure. Baseline liver enzymes, lipids, HbA1c and body composition are what let you show, six months later, that the treatment improved your health and not just your weight.
The Baseline Blood Panel
This is the panel typically arranged before starting GLP-1 therapy. Your doctor may add or drop tests based on your history — this is a guide to what a thorough assessment looks like, not a fixed prescription.
| Test | Why it is done before starting |
|---|---|
| HbA1c + fasting glucose | Establishes whether you have diabetes, prediabetes or normal glucose. This changes the treatment goal, the choice of agent, and whether any existing diabetes medicine needs adjusting when the GLP-1 starts. |
| Kidney function (creatinine, eGFR, urine ACR) | GLP-1 medicines are usable in most degrees of kidney impairment, but dehydration from vomiting or diarrhoea is the main way people get into trouble. Knowing your starting kidney function is what makes a later drop detectable. |
| Liver enzymes (ALT, AST, GGT) | Fatty liver is present in a large share of Indian patients seeking weight treatment, often silently. Baseline enzymes let improvement be tracked — frequently one of the clearest benefits of treatment. |
| Lipid profile | Triglycerides matter twice over: they are a cardiovascular risk marker, and very high levels are themselves a risk factor for pancreatitis, which is relevant to this drug class. |
| Thyroid function (TSH, with free T4 if abnormal) | Untreated hypothyroidism causes weight gain, fatigue and poor response to any weight programme. It should be corrected alongside, not ignored. |
| Complete blood count | Anaemia is common in Indian women, causes fatigue that would otherwise be blamed on the medicine, and also distorts HbA1c interpretation. |
| Vitamin B12 and vitamin D | Both are frequently low in Indian adults, particularly vegetarians and anyone on long-term metformin. Deficiency worsens the fatigue and hair-thinning that patients often attribute to the GLP-1 itself. |
| Serum lipase or amylase — only if indicated | Not a routine screening test. It is checked when there is a history of pancreatitis, gallstones, heavy alcohol use or very high triglycerides. |
| ECG and blood pressure | Simple, cheap, and part of any cardiometabolic baseline — especially in patients with diabetes, hypertension or a family history of early heart disease. |
| Pregnancy test where applicable | GLP-1 medicines are not recommended in pregnancy. In women who could become pregnant, this is discussed and confirmed before starting. See GLP-1, contraception and pregnancy planning. |
A note on calcitonin: patients sometimes ask for a calcitonin blood test to screen for thyroid cancer before starting. Routine calcitonin screening is not recommended for this purpose — it produces frequent false positives and leads to unnecessary procedures. What matters instead is the history question below.
The History That Matters More Than the Bloods
Most of the genuine contraindications to GLP-1 therapy are found by asking, not by testing. Expect to be asked about all of the following — and answer them fully even if they seem unrelated.
- Medullary thyroid carcinoma or MEN 2 in you or a blood relative. This is the principal absolute contraindication for the GLP-1 class. Ordinary thyroid problems — hypothyroidism, goitre, Hashimoto's — are not the same thing and do not rule out treatment.
- Any previous episode of pancreatitis, and any history of gallstones or gallbladder surgery.
- Severe reflux, gastroparesis or long-standing vomiting. These medicines slow the stomach, so pre-existing problems there tend to get worse.
- Type 1 diabetes, or diabetes with a history of ketoacidosis — a different clinical situation requiring specialist input.
- Diabetic retinopathy status in people with diabetes, since rapid improvement in blood sugar can transiently worsen existing retinopathy. A recent eye check is worth having.
- Pregnancy, breastfeeding, or plans to conceive in the next year.
- Your full medicine list, including insulin, sulfonylureas, thyroid tablets, blood thinners, contraceptives and anything bought over the counter. See GLP-1 medicines and your other prescriptions.
- Eating patterns and mental health. A history of restrictive eating, bingeing or purging changes how — and whether — appetite-suppressing medicine should be used. This is asked with care, not judgement.
- Alcohol intake, which interacts with both pancreatitis risk and liver findings. See GLP-1 and alcohol.
Two things that should stop a start, or at least pause it
A personal or family history of medullary thyroid carcinoma or MEN 2 syndrome, and an active or recent episode of pancreatitis. If either applies to you, tell the prescribing doctor before the first dose — not after. A fuller list is on who should not take these medicines.
Measurements, Not Just Weight
The number on a bathroom scale cannot distinguish fat lost from muscle lost — and muscle loss is the single most under-recognised problem in unsupervised GLP-1 use. A baseline should therefore include:
- Weight, height and BMI, interpreted against Asian-Indian thresholds, which are lower than the international ones.
- Waist circumference — a better guide to metabolic risk in South Asians than BMI alone.
- Blood pressure, taken properly, seated, after rest.
- Body composition on InBody 380 at Nirvana Clinic — used to track fat mass, skeletal muscle mass and body water over the course of treatment. It is a monitoring and assessment tool, not a diagnostic test, and it is what makes muscle loss visible early enough to act on. More on how InBody monitoring is used during GLP-1 therapy.
What a First GLP-1 Consultation Involves at Nirvana Clinic
- History and examination (30–40 minutes). Weight history, previous attempts, medicines, family history, eating pattern, sleep, alcohol, and what you are actually hoping treatment will change.
- Baseline investigations. The panel above, adjusted to you. If you have had recent tests elsewhere, bring the reports — repeating them is usually unnecessary.
- Review and decision. Whether a GLP-1 is appropriate, which agent suits your situation, or whether something else should be treated first. Sometimes the honest answer is that medicine is not the right next step, and we will say so.
- If we proceed: a written plan covering starting approach, dose escalation, expected side effects and how to manage them, a nutrition plan built around protein, and scheduled follow-up with repeat bloods and body composition.
Consultations are available in clinic near Delta-1 Metro and online for patients outside Greater Noida.
Assessment Led by Dr. Manuj Sondhi
MRCP (UK) · MD · DNB · Consultant Physician & Diabetologist
Dr. Manuj Sondhi brings 15+ years in metabolic medicine — diabetes, obesity, fatty liver and lipid disorders — and has applied that expertise to GLP-1 therapy since these medicines launched in India. His MRCP (UK) is an internationally recognised postgraduate qualification from the Royal College of Physicians, UK. Read his full profile.
📍 GF-93, Ground Floor, Sun Twilight Complex, opposite Delta-1 Metro Station, Greater Noida 201308 · In-clinic & online consultations
Frequently Asked Questions
Can I start a GLP-1 without any blood tests?
It happens often in India, but it is not good practice. Baseline tests are what identify people who should not take these medicines, uncover treatable causes of weight gain such as thyroid disease, and create the reference point against which any later problem is judged. Starting blind also means nobody can tell whether the treatment improved your health or only your weight.
How much do the baseline tests cost?
The panel is made up of standard laboratory tests that are widely available in Greater Noida and Delhi NCR. Exact charges depend on the laboratory and which tests your doctor selects for you, so we discuss the list at consultation rather than quoting a package price. If you already have recent reports, bring them — tests are rarely repeated unnecessarily.
I have hypothyroidism. Does that stop me from taking a GLP-1?
No. Ordinary hypothyroidism, goitre and Hashimoto's thyroiditis are not contraindications. The concern in the drug labelling relates specifically to medullary thyroid carcinoma and MEN 2 syndrome, which are rare and quite different conditions. What does matter is that your thyroid is adequately treated, and that thyroid tablet absorption is reviewed once the GLP-1 starts.
Do I need a calcitonin test or a thyroid scan before starting?
Routine calcitonin screening before GLP-1 therapy is not recommended, because it produces frequent false positives and leads to unnecessary investigation. What is required is a careful family and personal history of medullary thyroid carcinoma or MEN 2. Imaging is arranged only when there is a clinical reason, such as a palpable thyroid nodule.
How often are tests repeated after starting?
Typically at around three months and then six-monthly, with the exact schedule depending on your baseline results and whether you have diabetes, fatty liver or kidney impairment. Body composition is usually checked more often than bloods, because muscle preservation needs to be tracked while weight is falling.
Can these tests be done if I consult online?
Yes. For online consultations the tests are arranged at a laboratory near you and the reports are reviewed together before any treatment decision is made. Body composition assessment requires an in-clinic visit, so patients who consult online usually plan one visit when convenient.
Start With an Assessment, Not a Prescription
One structured consultation tells you whether GLP-1 therapy is appropriate for you, what is actually driving your weight, and what a safe plan would look like. Clinic near Delta-1 Metro, Greater Noida — or online.
Related reading: GLP-1 Therapy in India · Am I Eligible? · Dose Escalation · Managing Side Effects · Medical Weight Loss, Greater Noida