How long does it take to lose weight, and when do you start to notice?

There’s no one-size-fits-all approach to weight loss and no specific timeline of when you can or should expect to see particular results. Factors like genetics, diet, exercise habits and hormones all influence how quickly you lose weight.

While it can feel frustrating if progress is slower than expected, the important thing to remember is that weight loss is a lifelong journey, and how quickly you lose weight is not as important as whether you keep it off and maintain healthy habits.

In this guide, we’ll cover at which point most people start to lose weight with medication, what can influence weight loss rates, and h0w to track your progress.

Key Points:

• Weight loss looks different for everyone and depends on your metabolism, habits, and overall health.
• Early changes like better energy levels and improvements in how your body works may not always show on the scales straight away.
• Tracking progress besides weighing yourself, like taking photos and seeing how clothes fit, can help keep up your motivation.

How long does it take to lose weight? 

There is no single timeline for weight loss. It looks different for everyone, and there’s no amount of weight you’re supposed to have lost by a certain point.

Often, people find that weight loss happens steadily in the beginning of treatment and accelerates as you increase through doses, then may slow down again as you near your weight loss goals and reach the maintenance phase.

It’s important to remember that weight loss is a marathon, not a sprint, and that it is rarely consistent for long periods of time.

What affects the time it takes to lose weight

There are many factors that can affect how quickly you might lose weight, including:

• your starting weight
• your basal metabolic rate (BMR)
• your calorie intake
• your activity level
• your age
• your sleep habits
• your stress levels
• other health conditions you have 

Basal metabolic rate (BMR)

Your basal metabolic rate (BMR) is the term health professionals use to describe how many calories your body needs to perform essential basic functions (breathing, digestion, hair and nail growth, etc) at rest.

Factors that affect your BMR include: 

• your age
• your weight
• your body composition
• hormones levels
• habits

Knowing what your BMR is can help you set realistic daily calorie targets.

The higher your weight, the higher your BMR is likely to be. However, BMR is not only determined by weight, but also by body composition.

You can calculate your BMR easily using an online BMR calculator.

Calorie deficit level

A calorie deficit is when you’re burning more calories in a day than you consume through food and drink.

When you use more calories than you take in, your body uses the excess fuel stored in fat cells as energy, which over time can lead to weight loss.

However, this does not mean a bigger calorie deficit will necessarily deliver better results. An excessive calorie deficit can worsen or trigger side effects like fatigue, headaches, and nausea, and it can slow your weight loss progress. Remember, sustainability is key to weight loss.

Your prescriber can help you find the right calorie deficit to support effective and safe weight loss.

Exercise frequency and intensity 

Another major factor in how quickly you may see weight loss results is your activity levels, because how physically active you are throughout the day determines how many calories you burn.

Regular movement keeps your metabolism working properly, helps regulate blood sugar and energy levels, and improves circulation and bone density.

Consistency is more important than intensity when it comes to exercise. Starting slowly and gently and building up to regular exercise helps you:

• avoid injury
• adjust to your medication and new activity levels
• feel motivated throughout your treatment

Try to alternate between cardio and strength training, and leave at least one rest day between workouts to allow your body to recover properly.

Cardio exercises help improve heart health, increase stamina, and burn calories. They are particularly effective for supporting fat loss and boosting overall fitness.

Strength training helps build and preserve muscle mass, which is especially important during weight loss. The more muscle you maintain, the more energy your body burns at rest. This can help you burn more fat over time and support long-term weight maintenance.

Beginner-friendly cardio exercises you could try include:

• walking
• cycling
• swimming
• aqua aerobics
• tai chi

Strength training exercises to try include:

• beginner yoga and mobility exercises
• kneeling press-ups
• assisted squats
• assisted dips
• resistance band training

Age

Your metabolism naturally slows as you age, so older adults may find they lose weight more slowly than younger adults.

Keeping expectations and goals realistic is key to staying motivated and making your weight loss plan sustainable.

If you’re living with obesity, any weight loss, however small, can have health benefits. Did you know that every 1 kg of weight you lose reduces the pressure on your knee joints by 4 kgs? Moderate weight loss can also reduce inflammation and some disease risk.

Sleep and stress levels

Regular and good quality sleep is crucial both for weight loss and for overall health. As well as giving your cells time to repair and regenerate, sleep also helps regulate your hormones.

Insufficient sleep can raise cortisol levels and disrupt hormone levels in the body, all of which can make it harder to lose weight.

Medical conditions

Certain medical conditions or the medications that treat them can affect your ability to lose or maintain weight, including:

• sleep apnoea
• mental health conditions like depression and anxiety
• polycystic ovary syndrome (PCOS)
• insulin resistance

If you’re living with another medical condition while taking weight loss injections, make sure your prescribing team monitors your progress closely for safety and effectiveness.

How long does it usually take to notice weight loss results?

Most people start to feel the effects of weight loss injections from the very first dose, in the form of reduced appetite and more stable blood sugar levels.

During the first four weeks of treatment, you’ll be taking a low dose of the medication to give your body time to adjust. Because of this, most people don’t start seeing visible weight loss results until around weeks 5 to 8.

After increasing their dose again around week 9 is when most people start noticing significant weight loss changes on the scale and in the mirror.

However, remember that everyone is different, and how well you tolerate the medication and how quickly you lose weight might vary from someone else’s results.

What are the different ways you can measure weight loss?

There are many ways to measure your weight loss progress, including:

• your weight on the scale
• the fit of your clothes
• your body composition and muscle growth

Body weight changes 

Body weight naturally fluctuates from day to day due to things like water retention and hormonal cycles.

If you’re weighing yourself daily and notice you’ve not lost weight, or even that you’ve regained a small amount, this can be discouraging.

It may be better to weigh yourself weekly to get a more complete picture of your overall weight loss progress, so you can see how far you’ve come each week.

Changes in clothes sizes/fit

If your clothes are fitting more comfortably and feeling a little looser, that’s an indicator that you’re likely losing weight, even if it’s not showing on the scale.

You may even find that you need new clothes in smaller sizes after a while. 

Changes in physical appearance

You may be losing fat even if the numbers on the scale aren’t going down.

If you’re sticking to healthy eating habits and doing strength training exercises, it’s possible that you are losing fat while your weight stays the same, because the weight you’re gaining from new muscle replaces the weight lost from body fat.

Everyone’s body composition is unique, but people typically first notice weight loss in these areas:

• the waist
• upper arms
• around the lower jaw and in the face
• shoulders
• hips
• thighs
• buttocks

It’s easy to focus on the number on the scales when you’re trying to lose weight, but it only tells part of the story. You might notice your clothes fitting more loosely, have more energy throughout the day, or simply feel more confident in yourself.

These changes might not always show up as a big shift on the scales, but they are real progress. Paying attention to them can help you stay motivated on days when the number does not move, which is completely normal.

Ayesha Bashir, myBMI weight loss expert

Energy levels

Improved energy is one of the main signs of weight loss progress.

This will likely be due to the improvements in your overall health thanks to weight loss, and to giving your body more of the nutrients it needs by sticking to a healthy eating plan.

Blood pressure levels

Losing weight helps lower blood pressure by reducing the strain on your heart, which will have to work less hard to pump blood around your body if your weight is going down.

Losing weight also brings many overall health benefits which can extend and improve your life, including:

• increased metabolism
• improved blood pressure
• better regulated blood sugar
• better organ function
• reduced joint pressure and pain

How to track your weight loss 

There are many ways to track your weight loss progress besides just numbers on the scale.

To help keep yourself motivated by seeing the progress you’ve already made, you could try:

• taking photos
• journaling
• tracking other achievements besides weight loss (fitness milestones, for example)

Take photos 

Taking photos is a great way to track how your body is changing and responding to weight loss treatment.

Just remember to take your photos in consistent conditions to make accurate before-and-after comparisons.

For accurate photos:

• take photos at a similar time every day, ideally in the morning before you’ve eaten.
• use the same lighting conditions for every photo.
• take photos in the same spot every time.
• wear the same form-fitting clothing in every photo.
• use the same camera and camera angle every time.

Journaling 

Journaling is a great way to record your habits, patterns, results, and feelings about your weight loss journey.

You can use your journal however you want, but many people find it helps them to:

• reflect on their journey and preserve moments of motivation to return to on days when sticking to healthy habits feels less easy
• record any side effects or reactions to specific foods
• note any emotional or other triggers that can lead to emotional eating

 Track other achievements besides weight loss

Weight loss is just one aspect of your long-term health. Seeing changes in the mirror and on the scale is just one of the improvements to your health you’ll notice on your weight loss journey.

To keep yourself motivated, celebrate your non-weight related achievements too, like:

• fitness milestones, whether that’s jogging for 100 metres or running a marathon.
• habit consistency, like your first month sticking to an eating plan, a one-month streak of going for a short walk every day, or ten visits to the gym.
• how you feel in yourself, like an increase in your confidence or energy levels, better sleep or mood.

Frequently asked questions

How long does it take to lose weight?

Most people taking weight loss injections start feeling a reduction in their appetite straight away, and they may start to see visible weight loss results from weeks 5 to 8 onwards, as their dose increases.

Why am I not losing weight even though I am trying?

This could be due to many factors including not being in a big enough calorie deficit, hormonal imbalances, or your dose being too low. If you’re not seeing your desired weight loss results, talk to your prescriber.

Is faster weight loss better?

Faster weight loss is not necessarily better; in fact, it can make you more likely to regain weight. For most people, a safe rate of weight loss is around 2% of their starting body weight lost every month.

How much weight loss is realistic per week?

This depends on your starting weight, the strength of the dose you are on, and how long you’ve been taking your medication. Weight loss may slow or speed up with dose changes, and those with more weight to lose are likely to lose more weight faster, especially early on in treatment.

Can medication change how quickly I lose weight?

Yes, absolutely. Clinical trials have shown that you’re more likely to lose weight using weight loss medications than through healthy eating, exercise, and willpower alone.

Why does weight loss slow down over time?

Weight loss often slows down over time due to hormonal changes, and to your metabolism slowing down and adapting as your basal metabolic rate (BMR) drops with your weight. Talk to your prescriber about strategies to help break through weight loss plateaus.

Sources:

• Once-weekly semaglutide 7·2 mg in adults with obesity (STEP UP): a randomised, controlled, phase 3b trial. (2025) The Lancet [Accessed 4 February 2026)
• Strength Exercises. (2024) NHS [Accessed 4 February 2026]
• Tirzepatide once weekly for the treatment of obesity. (2022) JAMA. [Accessed 4 February 2026)
• Weight Loss Benefits for Arthritis. (2024) Arthritis Foundation [Accessed 4 February 2026]
• Your Weight and Your Blood Pressure. Blood Pressure UK [Accessed 4 February 2026]