10 Truths About Weight Loss Pens You Should Know Before Starting
Dr. Eve explains in a warm, easy-to-understand way — backed by real medical evidence.
Lately, many people have been asking me about weight loss pens — whether they really work, whether they are safe, and whether they might be the right option for them.
You may have seen dramatic transformations online, celebrity stories, or friends who suddenly lost weight. Naturally, this raises many questions:
- Do they really work?
- Are they safe?
- Will the weight come back after stopping?
- Do I need to stay on them forever?
- Which one is best?
Today, I’d like to share 10 important truths about weight loss pens you should know before starting treatment — in a simple, honest, and evidence-based way.
First, weight loss pens are not magic shortcuts. They are medical treatments used for overweight and obesity management, especially medications in the GLP-1 receptor agonist group and newer GLP-1 + GIP dual agonists, such as Semaglutide and Tirzepatide.
They help regulate hunger signals, improve fullness, reduce cravings, and support sustainable weight loss when combined with lifestyle changes.
1. Will the weight come back after stopping?
This is the most common question I receive.
The honest answer is: it can happen, but not to everyone.
Obesity is a chronic medical condition influenced by:
- hormones
- genetics
- sleep quality
- stress
- metabolism
- eating patterns
These medications help lower appetite and improve satiety. Once stopped, some people notice stronger hunger signals returning, which may lead to weight regain if there is no long-term plan.
That is why I always tell my patients:
The goal is not only to lose weight — but to maintain it well.
Long-term strategies may include:
- sustainable nutrition habits
- resistance training
- sleep optimization
- maintenance therapy when appropriate
Reference: Rubino D et al. Diabetes Obes Metab. 2022.
2. Do weight loss pens make your face look older?
Many people worry about this.
In reality, the medication itself does not “age” the face. What often happens is facial fat loss during weight reduction.
When weight decreases, some people lose volume in areas such as:
- cheeks
- temples
- jawline support areas
This can create a more tired or hollow appearance, especially in adults over 35, when collagen naturally declines.
Ways to reduce this risk:
- lose weight gradually
- eat enough protein
- strength train regularly
- maintain skin health
- avoid becoming excessively lean
Health always matters more than chasing the lowest number on the scale.
3. Are weight loss pens dangerous? Can they damage the liver or kidneys?
When properly prescribed and medically supervised, these medications are generally considered safe.
Common side effects may include:
- nausea
- early fullness
- bloating
- constipation
- reduced appetite
These often improve over time.
Regarding liver or kidney concerns:
- They do not typically cause direct liver damage in healthy individuals
- Kidney issues may happen indirectly if someone becomes dehydrated from vomiting or poor fluid intake
- Some metabolic markers may actually improve with weight loss
Before treatment, I usually assess:
- kidney function
- diabetes status
- gallbladder history
- pancreatitis history
- current medications
4. Why do some people not lose weight at all?
5. Do I need to starve myself while using them?
Absolutely not.
These medications are meant to help you eat more naturally and mindfully — not to suffer.
I encourage patients to focus on:
- protein at each meal
- vegetables and fiber
- fewer sugary drinks
- fewer processed snacks
- slower, mindful eating
Extreme restriction can lead to:
- fatigue
- dizziness
- muscle loss
- binge eating later
The best diet is one you can realistically sustain.
6. Can people who are not very overweight use them?
Sometimes yes, sometimes no.
Some people appear slim but still have metabolic risks such as:
- abdominal fat
- fatty liver
- prediabetes
- PCOS
These individuals may still benefit.
On the other hand, someone at a healthy weight who simply wants to lose 2–3 kg cosmetically may not be the ideal candidate.
Treatment decisions should consider:
- BMI
- waist circumference
- body composition
- metabolic health
7. Can they affect fertility or hormones?
This is an important question, especially for women planning pregnancy.
Current evidence does not show that these medications directly cause infertility.
In fact, for some patients with obesity or PCOS, weight loss may improve menstrual regularity and ovulation.
However:
- They are generally not recommended during pregnancy
- Pre-pregnancy planning is important
- Some medications should be stopped in advance
Always discuss family planning with your doctor first.
8. Is Tirzepatide better than older options?
Tirzepatide works on both GIP and GLP-1 pathways, which can produce strong results in both glucose control and weight reduction.
Clinical trials such as SURMOUNT-1 showed impressive average weight loss.
But “better” does not always mean “better for you.”
We still consider:
- budget
- side effect tolerance
- weight loss goals
- diabetes status
- long-term plans
Some patients do extremely well on Semaglutide and may not need to switch.
Reference: Jastreboff AM et al. NEJM. 2022.
9. Should I wait for newer triple-action medications next year?
Obesity medicine is evolving quickly.
New investigational drugs such as Retatrutide act on multiple pathways and early data are exciting.
But I often ask patients:
If you wait another year…
- will your weight continue rising?
- will fatty liver worsen?
- will diabetes progress?
- will joint pain increase?
For many people, starting treatment now may be more valuable than waiting for the next generation.
10. Do I need to stay on them forever?
Not necessarily.
Some people use them:
- short-term to initiate weight loss
- medium-term to stabilize progress
- long-term for chronic weight maintenance
It depends on:
- why the weight was gained
- history of yo-yo dieting
- lifestyle sustainability
- associated health conditions
There is no one-size-fits-all answer. Treatment should always be personalized.
have tried losing weight many times without success
regain weight repeatedly
struggle with constant hunger
have fatty liver
have PCOS
have diabetes or prediabetes
snore, feel tired, or have knee pain
A final message from Dr. Eve
Weight loss pens are not shameful, and they are not shortcuts.
They are medical tools that can genuinely help many people regain control of their health.
The most important question is not:
“Should I inject or not?”
It is:
“What is the healthiest and most suitable path for my body?”
Because true success is not only losing weight —
it is feeling healthier, stronger, and happier in everyday life.
References
Wilding JPH, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021.
Jastreboff AM, et al. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022.
Rubino D, et al. Weight regain after withdrawal of semaglutide. Diabetes Obes Metab. 2022.
Ludvik B, et al. Retatrutide for Obesity. N Engl J Med. 2023.
