In short
- GLP-1 agonists mimic a hormone the body produces itself, which suppresses appetite.
- With use, blood glucose, insulin sensitivity and sometimes liver function change.
- A baseline measurement before starting shows what changes afterwards.
- Bloodworks does not treat or prescribe medication, it provides insight into your values.
What you can measure
- HbA1c
- Glucose
- Insulin
- Liver enzymes (ALT + AST)
- Creatinine + eGFR
- Triglycerides
- Ferritin
- Vitamin B12
- Vitamin D
Not every cause is visible in blood. These are the values that most often explain something.
Recommended test
Aanbevolen als basislijn voor en tijdens een afval- of GLP-1-traject
Bloodworks Weightloss
29 markersEen afval- of GLP-1-traject raakt de suikerstofwisseling, de lever, de nier, de vetwaarden en de voedingsstatus tegelijk. Dit pakket dekt precies die domeinen in één afname en geeft een basislijn waarmee u een hermeting later kunt vergelijken.
- Personal assessment by a registered doctor
- Clear laboratory report, in plain language
- No referral needed
- 800+ blood draw locations
€349
Blood draw fee included at this amount.
Prefer something else?
- Blood sugar€49· Een lichtere eerste stap voor wie alleen de suikerstofwisseling wil volgen, met de nuchtere glucose en HbA1c naast elkaar.
- Bloodworks Premium€399· Een bredere blik voor wie naast de metabole waarden ook de volledige ijzerstatus en de vitamines en mineralen wil kennen, bijvoorbeeld bij een fors verminderde inname.
What are GLP-1 agonists?
GLP-1 stands for glucagon-like peptide-1, a hormone the body produces naturally after a meal. It suppresses appetite, slows gastric emptying, and stimulates insulin release.
GLP-1 agonists are medications that mimic this hormone. The best known is semaglutide, under the brand names Ozempic (for type 2 diabetes) and Wegovy (for weight management). Tirzepatide (Mounjaro) works on a similar principle but targets two hormone receptors.
These medications were originally developed for type 2 diabetes. The weight loss that occurred with use was so significant that they are now also used outside diabetes treatment, in the Netherlands through a limited number of clinics and an increasing number of online providers.
Why is blood testing relevant with GLP-1 use?
GLP-1 medications influence metabolism on multiple fronts. With use, blood glucose, insulin sensitivity, and sometimes liver function change. Those who already have an increased risk of metabolic problems, think insulin resistance, fatty liver, or abnormal liver enzyme levels, would do well to map that picture before and during use.
Which blood values are relevant?
The most relevant markers in medical weight loss and GLP-1 use are:
- fasting blood glucose and HbA1c (sugar metabolism)
- liver enzyme levels ALAT and ASAT (liver function)
- kidney function (creatinine, eGFR)
- lipid profile (cholesterol, triglycerides, HDL, LDL)
- insulin or C-peptide for those wishing to assess insulin resistance
In addition, there are markers that are indirectly relevant with significant weight loss:
- ferritin (iron stores can fall with reduced intake)
- vitamin D
- vitamin B12
- folic acid
Those who eat little also take in fewer micronutrients.
Want to have a baseline measurement done?
Alongside HbA1c, cholesterol, liver enzymes, ferritin, B12 and vitamin D, the Bloodworks Weightloss package includes the full Bloodworks Plus base check: 29 tests in a single blood draw.
Fasting or not fasting?
For a complete metabolic profile, including fasting glucose, insulin, and triglycerides, fasting blood draw is necessary. Fasting means at least twelve hours without food, water only. Bloodworks schedules blood draws early in the morning, so fasting is practical without disrupting your day.
What does a responsible programme look like?
Those who seriously want to lose weight with medical support begin with a baseline measurement before starting. A repeat measurement after three to six months is then worthwhile, with questions such as:
- have blood sugar values improved?
- how is the liver doing?
- have any deficiencies developed?
That data gives direction for next steps, regardless of whether you are taking medication or not.
Bloodworks does not carry out medical treatments and does not prescribe medication. We provide insight into your blood values, with interpretation by BIG-registered doctors. You can share that insight with the doctor or clinic supervising your treatment.