NewPeso: +900 success stories.Try it
Skip to content
AiONAiON
Peso

Weight loss
for life

Advanced weight-loss treatment. Find out for free in 4 minutes if you qualify. Limited places.

Peso
Weight loss
for life

Advanced weight-loss treatment. Find out for free in 4 minutes if you qualify. Limited places.

Peso

Weight loss for life.

Advanced weight-loss treatment. Find out for free in 4 minutes if you qualify. Limited places.

  • 900+ active patients
  • Prescription in under 24 h
  • 24/7 medical support
  • Weight-loss guarantee
  • Cancel anytime
  • 100% legal in Spain
  • 900+ active patients
  • Prescription in under 24 h
  • 24/7 medical support
  • Weight-loss guarantee
  • Cancel anytime
  • 100% legal in Spain

Lose weight and keep it off

Lose weight from home with the most advanced medical treatment and a team that stays with you so you keep it off over time.

  • Lose fat while keeping your muscle mass
  • Learn to manage your appetite
  • Medical report and personalised nutrition plan
  • 1:1 medical support · Weight-loss guarantee

+900 success stories. The next one can be yours. Shall we start?

Keep your muscle mass
Regulate your appetite
Avoid the rebound effect
EU-licensed doctors
Weight-loss guarantee
100% personalised plan
From home, no waiting

98%98%

of patients reach their goalof patients reach their goal

3.4 kg3.4 kg

average monthly loss per patientaverage monthly loss per patient

100%100%

muscle mass recoverymuscle mass recovery

100%100%

reach low-risk abdominal fatreach low-risk abdominal fat

Peso

Live well. Lose weight better.Lose fat. Keep muscle.

Lose 3–4 kg a month

The plan's target pace if you follow your medical team's guidance.

Peso

Live well. Lose weight better.Lose fat. Keep muscle.

Lose 3–4 kg a month

The plan's target pace if you follow your medical team's guidance.

Keep your muscle

What you lose is mostly fat: the plan protects your muscle mass.

Never feel on a diet

Nutrition guidance built around your life, not a menu to endure.

Keep it for life

At a healthy weight, stage two begins: making habits stick.

Want to reach yourgoal weight?

It's not magic — it's science. By regulating appetite and satiety, cravings fade and results last.

Dr. David Céspedes

Medical Director at AiON

Preventive MedicinePublic HealthObesity & metabolic health

Medical degree from the Complutense University, specialist in Preventive Medicine and Public Health with over 25 years of clinical experience. He oversees every protocol from start to finish.

Medical degree from the Complutense University of Madrid, specialist in Preventive Medicine and Public Health with a master's from the Carlos III Health Institute. With over 25 years of clinical experience, he personally oversees every protocol from start to finish.

Dr. David Céspedes

How much weight can you lose?

Your current weight

50 kg115 kg180 kg
17

kg estimated

Weight-loss potential

*Average 23% body weight loss over 72 weeks in clinical trials with next-generation treatments. Individual results may vary.

Start
today

Three steps. Four minutes. One life.

4 min

Free assessment

Your history, your weight and your goal. No account, no card, no waiting room.

< 24 h

Medical review

A licensed doctor studies your case. If you don't qualify, they tell you and you pay nothing.

Same day

Treatment

Prescription, diet and nutrition in your plan. Plus your portal with the medical team inside.

Lose weight. Or you don't pay

If you follow the plan and don’t lose weight, we refund your money.

Photographic recreation: the body on day 1 of the weight management programme

Get your body back

Feel like yourself again

Get your body back

Before

Day 1
Photographic recreation: the same body six months into treatment

Feel like yourself again

After

6 months
Photographic recreation: the body on day 1 of the weight management programme

Get your body back

Feel like yourself again

Get your body back

Before

Day 1
Photographic recreation: the same body six months into treatment

Feel like yourself again

After

6 months
Photographic recreation: the body on day 1 of the weight management programme

Get your body back

Feel like yourself again

Get your body back

Before

Day 1
Photographic recreation: the same body six months into treatment

Feel like yourself again

After

6 months
Photographic recreation: the body on day 1 of the weight management programme

Get your body back

Feel like yourself again

Get your body back

Before

Day 1
Photographic recreation: the same body six months into treatment

Feel like yourself again

After

6 months
Photographic recreation: the body on day 1 of the weight management programme

Get your body back

Feel like yourself again

Get your body back

Before

Day 1
Photographic recreation: the same body six months into treatment

Feel like yourself again

After

6 months
Photographic recreation: the body on day 1 of the weight management programme

Get your body back

Feel like yourself again

Get your body back

Before

Day 1
Photographic recreation: the same body six months into treatment

Feel like yourself again

After

6 months

AiON x Clínica Evolution

I lost 64 kilos and found the woman I dreamed of as a girl.

AiON x Clínica Evolution

54 kilos lighter, with the energy of 15 years ago.

AiON x Clínica Evolution

44 kilos and one CPAP machine lighter: my kids say they have a new dad.

Start today

Three steps. Four minutes. One life.

  1. 4 min

    Free assessment

    Your history, your weight and your goal. No account, no card, no waiting room.

  2. < 24 h

    Medical review

    A licensed doctor studies your case. If you don't qualify, they tell you and you pay nothing.

  3. Same day

    Treatment

    Prescription, diet and nutrition in your plan. Plus your portal with the medical team inside.

Start with step one

Lose weight. Or you don't pay

If you follow the plan and don’t lose weight, we refund your money.

Peso

For those who take itseriously

Peso is not for everyone. If you are serious, it is for you.

When nothing else worked, this did

What to expect?

Month

1

Kick-off

Appetite drops and the weight really starts to move.

Peso

What's your goal?

Continue
AiON pen on a podium

Better doctorsBetter care

Meet the AiON team, with more than 40 years in practice combined.

  • Dr. David Céspedes
    • Preventive medicine & public health
    • Obesity & metabolic health

    Dr. David Céspedes

    Medical Director

    Physician specialized in Preventive Medicine. Oversees every protocol.

    Medical degree from the Complutense University, specialist in Preventive Medicine and Public Health with a master's from the Carlos III Health Institute. He oversees every protocol from start to finish.

  • Rubén Bravo
    • Obesity & metabolic health
    • Nutrition & dietetics

    Rubén Bravo

    CEO, Clínica Evolution

    Founder of Evolution. Leading voice on obesity and habits in Spanish media.

    Founder and CEO of Clínica Evolution. For over 15 years a leading voice on obesity and healthy habits in major Spanish media; today he leads a pioneering team in obesity and advanced biomedicine.

  • Camila Villanueva
    • Metabolic health
    • Body composition

    Camila Villanueva

    Clinical & Sports Nutritionist

    Clinical and sports nutritionist, expert in obesity.

    Dietitian-nutritionist with a master's in Sports Nutrition, specialised in obesity and body recomposition. Clinical experience across Colombia, the United States and Spain, including Olympic-level athletes.

  • Ximena Rodríguez
    • Metabolic nutrition
    • Diabetes & insulin resistance

    Ximena Rodríguez

    Clinical Nutritionist

    Clinical nutritionist, expert in diabetes and bariatric surgery.

    Over 5 years of experience in specialised practice and hospital management. Expert in type 2 diabetes and bariatric patients, currently studying an MSc in Human Nutrition at the Complutense University of Madrid.

  • Irene García
    • Obesity
    • Eating behaviour

    Irene García

    Nutritionist specialised in obesity

    Nutritionist specialized in obesity and eating behavior.

    Graduate in Human Nutrition and Dietetics from the Complutense University, with a master's in Eating Behaviour Disorders. Specialised in obesity, digestive conditions and sustainable habits.

Peso

What the media sayThe media talk about us Our medical team has appeared in

BBVA

«No solo es comer menos: el metabolismo, el descanso y las hormonas también deciden.»

ABC

«Si tus padres tienen entre 50 y 60 años y no hacen deporte, no serán independientes a los 70.»

El Confidencial

«La masa muscular que se pierde a los cincuenta es la autonomía que falta a los setenta.»

AS

«El ejercicio, a partir de los cincuenta, deja de ser opcional.»

El Español

«Para mantener este físico con 52 años hago estos ejercicios cinco días por semana.»

Telemadrid

«Asesor médico del programa, dos temporadas al lado de quienes empiezan.»

Frequently asked questions

What exactly is Peso?

Peso is Spain's first next-generation medical weight-loss protocol, with the most effective authorised pharmacological prescription under endocrinologist criteria. It combines a real medical prescription, a personalised report, 1:1 follow-up with a licensed doctor and 24/7 support via AiON. It's not an online pharmacy or a chatbot: it's a real clinical protocol, run end-to-end by healthcare professionals.

Is it legal to access this treatment in Spain?

Yes, completely legal. The medication prescribed in Peso is approved by the AEMPS and the EMA for the treatment of obesity and overweight with comorbidities. To obtain it you need a medical prescription issued by a licensed physician in Spain, which is exactly what Peso provides if you qualify clinically. It's dispensed at authorised pharmacies, like any prescription medication.

Why is Peso's treatment more effective than other options?

Most pharmacological weight-loss treatments act on a single appetite-regulation pathway. The one Peso prescribes, when you qualify clinically, acts simultaneously on two pathways that regulate appetite, satiety and glucose metabolism.

Clinical trials show average weight loss of up to 22.5% with this option versus 15% for conventional alternatives, with better digestive tolerability. At Peso we don't prescribe the most well-known. We prescribe the most effective.

What does the initial medical assessment involve?

It is a clinical questionnaire of around 4 minutes covering your medical history, current medication, BMI, comorbidities and goals. A registered doctor in Spain reviews your case individually and lets you know within 24 hours whether you are a suitable candidate for the protocol. It is completely free and with no commitment: you only pay if you qualify and decide to start.

What exactly does the Peso protocol include?

Each protocol includes: a free initial medical assessment, a next-generation prescription when the endocrinologist deems you a clinical candidate, a personalised medical report with a nutrition and habit plan adapted to your profile, 1:1 medical support throughout treatment, dose adjustments based on progress and 24/7 support via AiON. The report is yours forever, whether you continue with the treatment or not.

How much does Peso cost and how is the medication paid for?

The initial medical assessment is completely free. The cost of the protocol (consultations, personalised report, follow-up and 24/7 support) is communicated at the end of the assessment, before any commitment, because it depends on the estimated treatment duration.

The medication is billed separately and managed directly with the pharmacy where you collect it, according to your doctor's prescription. We do not resell medication: the price you pay at the pharmacy is the official price authorised in Spain.

How is the medication delivered? Will it arrive at my home?

Spanish legislation does not allow the direct shipment of prescription medication outside authorised pharmacies. So once your doctor issues the prescription, you take it to the pharmacy of your choice to collect the prescribed treatment. Many pharmacies also offer their own home-delivery service, so you can receive it at home in a fully legal and traceable way.

What does the weight-loss guarantee consist of?

From the third month on, if you follow the medical team’s guidelines and don’t lose weight, we refund your money. Your doctor documents your progress at each review. The exact conditions are detailed before treatment begins and in our Refund Policy. The medication itself, as it is managed directly with the pharmacy, is not included in the refund.

Who is behind Peso? Will I actually speak to a real doctor?

Yes, always. Your assessment, prescription and follow-up are carried out by a doctor registered in Spain, never by an algorithm. The team is led by Dr. David Céspedes, a specialist in Preventive Medicine and Public Health with experience in obesity, metabolic health and longevity. AiON is used as 24/7 support between consultations, but clinical decisions are always made by a healthcare professional.

Who can be a candidate for Peso?

Peso is intended for adults with a BMI compatible with pharmacological treatment for obesity, or overweight with comorbidities, according to the clinical guidelines in force in Spain. There are contraindications and precautions (among others: pregnancy and breastfeeding, personal or family history of medullary thyroid carcinoma, MEN2, pancreatitis, certain digestive conditions, or specific medications). That is why the medical assessment is mandatory: if you are not a candidate, we will tell you so transparently and the treatment will not be initiated.

Medical guides

Your health, always one step aheadYour health, always one step ahead

Your health, always one step aheadone step ahead

Join to get doctor-backed advice, product news and exclusive offers straight to your inbox.

By subscribing, you agree to our Terms of Service and our Privacy Policy.