Losing weight changes more than the number on the scale. Blood sugar, cholesterol, liver and kidney markers can all shift along the way, sometimes for the better and sometimes in ways worth keeping an eye on. That is especially true now that weight-loss medicines have become common.
This article explains what the weight-loss blood test panels in the BPR Clinic catalogue measure, where leptin fits, and how often people tend to repeat them.
Why weight-loss medicines changed the picture
Medicines such as semaglutide (sold as Wegovy and Ozempic) and tirzepatide (Mounjaro) belong to a group that acts on the GLP-1 hormone pathway. The NHS explains that semaglutide works for weight loss by reducing appetite and helping you feel fuller for longer, and that it is only available on prescription, either NHS or private. It also warns that some websites sell fake weight-loss medicines and that private prescriptions should come from a registered pharmacy.
In a large trial in adults with overweight or obesity, people taking weekly semaglutide alongside lifestyle support lost an average of 14.9% of their body weight over 68 weeks, compared with 2.4% with placebo (Wilding et al., 2021). The most common side effects were nausea and diarrhoea, usually mild to moderate and temporary.
A review of semaglutide safety concluded that it mostly causes mild-to-moderate, short-lived digestive symptoms and increases the risk of gallbladder problems such as gallstones (Smits and Van Raalte, 2021). Pancreatitis is discussed in the same review as a rare concern. This is why the LML designed panels that look at several organs at once.
What the weight-loss panels measure
Weight-loss management
According to the LML, the Weight-loss management panel covers:
- Kidney function: creatinine, urea, eGFR and sodium, relevant to hydration and to how the kidneys cope with rapid change.
- Liver health: ALT, AST, ALP, GGT, bilirubin, albumin, globulin and total protein.
- Cholesterol: total, HDL, LDL, triglycerides and HDL percentage, to follow cardiovascular risk as weight changes.
- Blood sugar control: HbA1c, the long-term marker of glucose.
- Pancreatic enzymes: amylase and lipase.
Weight-loss management + Thyroid
The Weight-loss management + Thyroid panel adds TSH and free T4. The LML includes them to identify or follow thyroid-related factors that can make weight loss harder.
Weight-loss management Advanced
The Weight-loss management Advanced panel goes further, with more than 42 markers according to the LML. On top of the above, it adds a full blood count, iron studies, vitamin B12 and vitamin D. These matter because eating less can also mean taking in fewer nutrients, and the panel is designed to follow nutritional status during a weight-loss programme.
Where leptin fits
Leptin is a hormone made by fat cells. It signals to the brain how much energy the body has stored and helps regulate appetite. A review in Frontiers in Endocrinology explains that in many people with obesity the brain responds less to leptin, a state called leptin resistance, which is linked to reduced feeling of fullness and higher food intake (Obradovic et al., 2021).
The Leptin test measures this hormone in the blood. According to the LML, raised levels may be seen with obesity, metabolic syndrome and insulin resistance, while low levels can be associated with very low body fat or undernutrition. It is not a routine test; it is usually added when a professional wants more detail on appetite regulation.
When these tests tend to make sense
As a general orientation, people often do a panel at the start of a weight-loss plan and then every 3 to 6 months while it continues. The LML describes the panels as suited to:
- people using, or planning to use, a GLP-1 weight-loss medicine;
- people who want to follow the safety and effect of their treatment;
- people advised by their GP or specialist to monitor organ function while on medication.
They can also be useful for anyone making a significant change through diet and activity alone. Talk to a healthcare professional about which panel fits your situation and how often to repeat it.
