How long does it take for GLP-1 RAs (Semaglutide: Ozempic, Wegovy) to work?
Key Takeaways
It takes about 8 to 12 weeks of treatment with a GLP-1 RA to start seeing the full effect.
The starting dose of these medications is low, to allow the body time to adjust. This helps to minimize side effects. The dose is usually increased after 4 weeks.
After the dose is increased, it takes another 4 to 5 weeks for the medication to build up in the body.
People generally continue to lose weight on a GLP-1 RA for a year or even longer. Weight loss occurs gradually over time.
GLP-1 RAs can have some side effects, which are mostly related to the digestive system. However, there have been very few serious side effects found, and these medications are considered safe for both short-term and long-term use.
A class of medications known as glucagon-like peptide 1 receptor agonists, or GLP-1 RAs, has been receiving a lot of interest lately. These medications help to keep blood sugar under control, and they can also help to promote weight loss.
In Singapore, some of these medications are approved for weight loss, including Wegovy (semaglutide) and Saxenda (liraglutide). There are also several GLP-1 RAs that are approved for treating diabetes, including Ozempic (semaglutide), Rybelsus (semaglutide), Victoza (liraglutide), and Trulicity (dulaglutide).
When a person starts a new medication, they’re often hoping to see results right away. However, with GLP-1 RAs, it generally takes some time to start seeing the results of the treatment. It helps to know what to expect, so you can be prepared. How long does it take for a GLP-1 RA to start working? How long will it be until you see the full results?
How do GLP-1 RAs work?
GLP-1 RAs act by mimicking a hormone known as glucagon-like peptide 1, or GLP-1. This hormone is involved in several aspects of the process of digestion and managing nutrients. Because of this, GLP-1 RAs have several different effects in the body. These medications:
Slow down emptying of the stomach after a meal. This helps to keep you feeling full for longer, which reduces how much you eat.
Reduce cravings and emotional eating. GLP-1 RAs appear to act in the brain as well. They help to reduce food cravings, and make you much less likely to reach for unhealthy foods in order to deal with challenging emotions.
Stimulate the release of insulin from the pancreas. Insulin is a hormone that’s normally released when your blood sugar is high, and it helps to cause your cells to take up sugar from the blood, which lowers blood sugar levels.
Block the release of sugar from the liver. When you’ve not eaten for a period of time, your liver will release sugar in order to increase your blood sugar levels. GLP-1 RAs prevent the liver from releasing too much sugar, which helps to keep your fasting glucose levels from rising too high.
In general, GLP-1 RAs help to keep blood sugar under control and also promote weight loss. Although all GLP-1 RAs work by a similar mechanism, certain ones are approved for treating diabetes, while others are approved for weight loss. The difference is mainly in the dose of the medication that’s used.
How long does it take for semaglutide to work
In general, it takes about 8 to 12 weeks of using a GLP-1 RA to notice more significant effects. There are a few reasons why this is the case.
Changes in dose
When you first start taking a GLP-1 RA, you begin at a low dose. This allows your body to get used to the medication. Starting at a higher dose would likely result in more side effects. By beginning at a small dose, the body is able to gradually adjust, which reduces the side effects. In general, this low dose is taken for the first four weeks, and then the dose is increased.
The low dose that you start with is generally not enough to have significant effects on your blood sugar or weight. Some people do notice a bit of a reduction in their blood sugar control from this small dose, but the effect is generally small. This is simply because you’re not yet taking a full dose of the medication.
After the first four weeks, your dose will be doubled. You won’t notice any difference in how you take the medication. This dose is considered to be the minimum therapeutic dose of the GLP-1 RA, meaning that it’s the lowest dose that’s expected to have a significant effect on your blood sugar and body weight.
Some people stay at this minimum therapeutic dose, while others will get a benefit from increasing it again a few weeks later. You and your doctor will work together to determine what dose is needed to get good results while minimizing the side effects.
Reaching steady state
Besides the changes in dose, the medication also builds up gradually in the body over time. After a GLP-1 RA is started or the dose is increased, it takes about 4 to 5 weeks for the medication to build up to full strength, which is known as “steady state.” The effects will increase gradually over this period of time.
For the first 4 weeks on a GLP-1 RA, you’ll be taking a small dose in order to adjust to the medication. Once the dose is increased, it takes about 4 more weeks for the medication to build up to the new higher level. This is why, after approximately 8 weeks, you’ll likely start to notice more of an effect of the treatment.
Gradual weight loss
Once the medication has reached its maximum concentration and is exerting its full effect, it takes quite a bit of time to lose weight. It’s actually better not to lose weight too quickly – this can lead to health issues like gallstones, and may also not be sustainable over the long term. It’s usually best to aim for losing about 0.5 to 1kg per week.
The suppression of appetite caused by a GLP-1 RA will likely lead you to eat less overall, and to reach for unhealthy foods less frequently. This means that you’ll be taking in fewer calories. If your activity levels remain the same or increase, then your body will use stored fat for energy to make up the deficit. Slowly, your body weight will go down. This does take time, but you’ll see the benefits in your energy levels and your health.
Studies have shown that people continue losing weight on a GLP-1 RA for a year or even longer. Weight loss occurs gradually over this period of time. Eventually, weight loss reaches a plateau, and body weight stabilizes at a lower level.
Side Effects of GLP-1 RAs
GLP-1 RAs are generally considered to be safe medications overall. However, like any medication, they can cause side effects. Because these medications act on the digestive system, it’s not surprising that many of the side effects are related to digestion. The most common side effects of GLP-1 RAs include:
Nausea and vomiting
Abdominal pain and bloating
Indigestion or acid reflux (heartburn)
Constipation or diarrhea
Weakness during exercise
Headache
These side effects may be bothersome, but are not dangerous. They can generally be managed by making some lifestyle adjustments. For example, taking smaller meals, avoiding lying down soon after a meal, drinking more fluids, and taking a snack before exercising can all help to make you more comfortable while you’re taking a GLP-1 RA.
Starting with a lower dose and then increasing it gradually helps to reduce the side effects that you experience, by allowing your body to adjust to the medication over time.
Long term use of GLP-1 RAs
People who take a GLP-1 RA for diabetes often stay on it for the long term, in order to help keep their blood sugar under control. Keeping your blood sugar from rising too high greatly reduces the risk of complications from diabetes, such as vision loss and kidney damage. It’s important to achieve consistent long-term blood sugar control in order to protect your health.
Even though weight loss reaches a plateau after about a year or so, people who take a GLP-1 RA for weight loss might still prefer to stay on it for the long term. This is because, after stopping the medication, it’s common for people to regain part of the weight that they lost while they were taking it. This weight regain is not inevitable, and there are ways to combat it. However, some people choose to keep taking a GLP-1 RA for the long term in order to help maintain their new healthier weight.
The widespread use of GLP-1 RAs is relatively new, and we don’t yet have enough long-term data on these medications to definitively state that long-term use carries no risks. We will have to wait for a few decades to gather enough data to be sure. However, the data that we have so far indicates that long-term use of GLP-1 RAs is safe.
One study followed people taking semaglutide for two years and found no major safety concerns. Another study followed people taking exenatide (another GLP-1 RA which is approved for treating diabetes) for six years and also discovered no major safety issues.
There’s a possible increase in the risk of gallbladder disease in people taking semaglutide for more than six months. However, weight loss itself increases the risk of gallbladder disease, so it’s hard to be sure that it’s the semaglutide that’s causing the issue. In addition, this side effect is quite uncommon, with only 36 cases being reported to the United States FDA over a 16-year period.
Overall, it’s considered safe to use GLP-1 RAs for the long term. We will have to wait for more data to be sure that there aren’t any unknown risks that show up after many years, but this is not expected to be the case. If you choose to use one of these medications for the long term in order to help control your blood sugar or maintain your weight loss, this is generally considered to be a safe option.
Supporting healthy blood sugar and weight loss on a GLP-1 RA
GLP-1 RAs have been shown to be effective for blood sugar control and weight loss. However, they’re not intended to replace lifestyle measures, such as a healthy diet and exercise. A GLP-1 RA should be thought of as an addition to a healthy lifestyle, rather than a replacement.
In order to develop a healthy lifestyle plan that’s sustainable for you, it helps to have support from professionals, such as health coaches and nutritionists. In addition, a GLP-1 RA needs to be prescribed by a doctor, who will also need to oversee your treatment to ensure that you’re staying safe and healthy. Our NOVI Optimum Plus program includes medical supervision along with consistent support from a team of health professionals. This helps to get the best possible results and protect your long-term health.