Can GLP-1 agonists reduce cravings for alcohol and nicotine?
There are serious indications that GLP-1 agonists such as semaglutide can curb cravings for alcohol and nicotine, but clinical evidence from trials in humans is still too limited to establish this with certainty. Do not use them outside their official indication for this purpose for the time being.
Animal research shows that GLP-1 agonists such as exenatide and liraglutide substantially reduce alcohol consumption. In mice, rats and monkeys, the motivation to drink alcohol, self-administration and relapse all decreased. The mechanism most likely runs through the brain's reward system, in particular via the signalling molecule dopamine. Stress regulation and cognitive processes may also play a role, although the precise mechanism has not yet been fully elucidated.
In humans the picture is less clear-cut, but there are genuine indications. Research based on Swedish patient data (more than 227,000 people with an alcohol use disorder) showed that semaglutide was associated with a hazard ratio of 0.64 for hospital admission due to alcohol-related problems, and liraglutide with a hazard ratio of 0.72, compared with periods of non-use in the same individuals. That is a stronger association than has been found for officially approved medications for alcohol addiction. However, this is not a randomised experiment, so cause and effect cannot be established.
For nicotine, a large analysis of electronic health records in the US, involving more than 222,000 people with diabetes, points to a clear difference: semaglutide users had significantly fewer healthcare contacts for tobacco addiction than people using other diabetes medications, including other GLP-1 agonists. Notably, that reduction occurred within 30 days of starting treatment. Here too, this represents an association in patient data, not proof that semaglutide itself is responsible.
Clinical evidence from actual trials is still scarce. Of the 5 trials in humans that met the selection criteria, 3 showed a positive effect on alcohol or nicotine addiction; 2 found no effect. Both reviews examining this conclude that it is too early to prescribe GLP-1 agonists outside their official indication for addiction. Genetic research also provides context: people with certain variants in the GLP-1 receptor gene have a higher risk of alcohol addiction and drink more on average when given intravenous access to alcohol. This suggests that the GLP-1 system is biologically relevant to addictive behaviour, but it does not prove a causal relationship.
This answer draws on animal research (mice, rats, monkeys), large analyses of patient data (a Swedish cohort of more than 227,000 people, a US records analysis of more than 222,000 people), and a handful of clinical trials in humans. The animal research is consistent and robust; the human evidence is based on associations in patient data and is therefore vulnerable to confounding factors. The researchers behind the clinical reviews emphasise that only 5 usable trials were available and that the results are mixed. The evidence for a causal effect in humans is therefore not yet conclusive.
Do GLP-1 agonists have a neuroregenerative effect on nerve cells?
GLP-1 agonists show strong indications of protective and restorative effects on nerve cells in animal research, but results in humans have been mixed so far. The agents have not been approved for this indication; consult your doctor if you would like to know more.
Does the timing of your meals affect how well you sleep?
Eating late is associated with taking longer to fall asleep and poorer sleep quality, although cause and effect have not always been proven. Try to have your last meal at least two to three hours before bedtime and limit evening snacks, especially if you already have difficulty sleeping.
Is reading every day good for your brain in the long run?
Daily reading is associated with a lower risk of dementia and greater cognitive resilience in later life. Whether reading itself causes that protection or is a sign of pre-existing brain fitness has not yet been fully resolved, but there is enough reason to simply start or continue.
What is the optimal vitamin D level?
For bone health, 50 nmol/l is the most widely accepted target level, achievable with 800 IU per day. Whether a higher level also provides benefit beyond bone has not yet been demonstrated.
Can GLP-1 agonists improve heart function?
GLP-1 agonists, and in particular semaglutide and tirzepatide, demonstrably reduce the risk of heart failure worsening in people with a specific form of heart failure; if you have this condition or type 2 diabetes, discuss with your cardiologist whether these agents are appropriate for you.
Do GLP-1 medications cause suicidal thoughts?
The available research gives no indication that GLP-1 medications cause suicidal thoughts; several large studies actually point to a lower risk. If you have doubts or concerns, discuss them with your doctor.