Peptides have become one of the most talked-about topics when it comes to weight loss, physical performance, rejuvenation, and longevity. Promoted on social media as "intelligent molecules" capable of accelerating aesthetic and metabolic results, they have begun to gain prominence.

But after all, what really are peptides? Do they work? Are they safe? And why are some approved for medical use while others still generate controversy?

What are peptides?

Peptides are small chains of amino acids, structures that function as "biological messengers" within the body. They naturally participate in various physiological processes, such as hormone production, metabolism control, tissue repair, immunity, and cell growth.

In practice, many peptides work by stimulating specific receptors in the body, triggering directed biological responses. It is precisely this characteristic that sparked the interest of modern medicine.

Some of them have already been used for years in endocrinology, diabetology, and gastroenterology. Others are still in the experimental phase or have restricted use.

Where do peptides act in the body?

The site of action depends on the type of peptide used.

Some act in the brain, especially in areas related to appetite control and satiety. Others act in the pancreas, stimulating insulin release. There are also those that act in muscle tissue, skin, the immune system, or the gastrointestinal tract.

The most well-known currently are GLP-1 receptor agonists, used mainly for the treatment of type 2 diabetes and obesity.

These medications help to:

  • reduce appetite;

  • increase the feeling of satiety;

  • delay gastric emptying;

  • improve glycemic control;

  • assist in weight loss.

Examples of most well-known peptides currently

Among the most discussed peptides are:

  • semaglutide;

  • tirzepatide;

  • liraglutida;

  • tesamorelin;

  • ipamorelin;

  • BPC-157;

  • CJC-1295;

  • collagen peptides.

Some have formal approval for certain diseases. Others are used experimentally, compounded, or even without robust scientific backing.

What already has medical approval?

Medications such as semaglutide and liraglutide have approval in various countries for type 2 diabetes and, in some specific formulations, also for obesity. Tirzepatide has been gaining ground due to significant results in weight loss and metabolic control.

In Brazil, use depends on the indication approved by the National Health Surveillance Agency, in addition to individualized medical evaluation.

Meanwhile, other peptides promoted for "anti-aging," muscle hypertrophy, or accelerated regeneration still do not have broad authorization, especially for aesthetic purposes. Many lack long-term studies on efficacy and safety.

This is one of the main current problems: the trivialization of use without medical criteria.

The side that barely appears on social media

Although the results shared on social media are frequently impressive, inappropriate use can bring important risks.

Among the possible side effects are:

  • nausea;

  • vomiting;

  • constipation;

  • diarrhea;

  • excessive loss of muscle mass;

  • dehydration;

  • hypoglycemia;

  • pancreatitis;

  • important gastrointestinal changes;

  • hormonal disorders.

In some cases, the problem is not just the peptide itself, but the source of the substance used.

Informal commercialization, manipulations without rigorous control, and use without medical supervision significantly increase the risks.

When can peptides really be indicated?

Imagine the following clinical scenario:

A 46-year-old woman with obesity, high blood pressure, and prediabetes has tried multiple weight loss strategies over the years. She presents with binge eating, difficulty adhering to diet, and progressive worsening of metabolic tests.

After complete medical evaluation, lifestyle changes, and appropriate clinical investigation, the use of a GLP-1 agonist can be considered as part of treatment.

In this context, the goal is not just aesthetics. There is metabolic benefit, cardiovascular benefit, and reduction of disease progression risk.

This is a classic example where use may be pertinent and based on scientific evidence.

When should use NOT happen?

The problem arises when substances are used without clinical necessity, only due to aesthetic pressure or the promise of quick results.

People with eating disorders, patients without metabolic evaluation, individuals with medical contraindications, or users seeking "shortcuts" for weight loss may experience important complications.

There is also concern about use associated with protocols promoted as "miraculous," especially in environments without adequate medical supervision.

Furthermore, many peptides sold as a solution for rejuvenation or muscle gain still have limited evidence.

The hype of longevity and the challenge of evidence-based medicine

The discussion about peptides is part of a larger trend: the search for longevity, performance, and optimization of the human body.

Scientific interest in the field is real and growing rapidly. However, there is an important difference between promising research and widespread use without sufficient proof.

In medicine, enthusiasm does not substitute for evidence.

Therefore, any treatment should consider:

  • real benefit;

  • safety;

  • patient profile;

  • correct indication;

  • clinical follow-up;

  • long-term risks.

Information is different from encouragement

The growing interest in peptides shows how the population is increasingly engaged with topics related to metabolic health, aesthetics, and quality of life.

But it is essential to remember that not every novelty is automatically safe for everyone.

Each body has its own characteristics, specific contraindications, and individual needs. The use of these substances requires responsible medical evaluation, adequate follow-up, and careful analysis of available scientific evidence.

This content is exclusively informative and educational in nature. It does not replace medical consultation, individualized diagnosis, or professional follow-up. Never use medications, hormones, or peptides on your own.

Dr. Rebeca Soares Andrade CRM-GO 39335