This page summarises what clinical trials and prescribing labels report. It is not a treatment plan and it does not tell you how to adjust a dose. If you are on an approved medicine, dose changes belong with the licensed Philippine physician who prescribed it.

GLP-1 medicines: what the trials reported

Semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro) have the best adverse-event data of anything on this site, because they went through large placebo-controlled trials.

The common effects are gastrointestinal. GLP-1 drugs slow the rate at which the stomach empties and act on appetite centres in the brain. The result is fullness, and for many people nausea, diarrhoea, vomiting, constipation, reflux, burping and bloating.

  • In STEP 1 (semaglutide 2.4 mg weekly, 68 weeks), nausea and diarrhoea were the most common adverse events. They were typically transient, mild to moderate, and subsided with time. Gastrointestinal events led 4.5% of semaglutide participants to stop treatment, against 0.8% on placebo.
  • In SURMOUNT-1 (tirzepatide, 72 weeks), the most common adverse events were gastrointestinal, mostly mild to moderate, and occurred mainly during dose escalation. Adverse events of any kind led to discontinuation in 4.3%, 7.1% and 6.2% of participants on 5, 10 and 15 mg, against 2.6% on placebo.

The pattern in both trials is the same: effects concentrate in the weeks after a dose step and fade for most people. That is the reason approved labels start low and step up slowly.

The Wegovy label lists the adverse reactions seen in at least 5% of patients: nausea, diarrhoea, vomiting, constipation, abdominal pain, headache, fatigue, indigestion, dizziness, abdominal distension, burping, low blood sugar in people with type 2 diabetes, flatulence, gastroenteritis, reflux and nasopharyngitis.

Retatrutide adds a signal the older drugs do not show. In the TRIUMPH-4 trial, dysesthesia (abnormal skin sensation such as tingling or burning) was reported in 20.9% of participants on 12 mg against 0.7% on placebo. Retatrutide is not an approved medicine; see the retatrutide page.

The less common risks on the labels

The Wegovy label's warnings section is a useful map of what doctors watch for with this drug class:

  • Acute pancreatitis. Severe, persistent abdominal pain, sometimes radiating to the back.
  • Gallbladder disease. Gallstones and inflammation, more likely with rapid weight loss.
  • Low blood sugar when combined with insulin or a sulfonylurea.
  • Acute kidney injury from dehydration. Vomiting and diarrhoea drain fluid. In Philippine heat, where you already lose more through sweat, this deserves attention. Oral rehydration salts, sold at every drugstore, exist for exactly this.
  • Serious allergic reactions, including anaphylaxis and angioedema.
  • Diabetic retinopathy complications in people with type 2 diabetes.
  • Heart rate increase. The label reports mean rises of 1 to 4 beats per minute over placebo.
  • Suicidal thoughts. The label advises monitoring for depression or unusual changes in mood.
  • Aspiration during anaesthesia. Because the stomach empties slowly, tell the doctor or anaesthetist before any procedure with sedation.
  • Thyroid C-cell tumours. Seen in rodents; the label contraindicates use with a personal or family history of medullary thyroid cancer or MEN 2.

The label also notes average rises in the pancreatic enzymes amylase and lipase during treatment, which is why these numbers need interpreting by a doctor rather than on their own. The bloodwork guide covers monitoring.

Injection-site reactions

Any subcutaneous injection can cause a local reaction: redness, itching, a small bruise or a tender bump. How often depends a lot on the product.

  • On the Wegovy label, injection-site reactions were reported in 1.4% of patients against 1% on placebo.
  • On the tesamorelin (Egrifta SV) label, the figure was 25% against 14% on placebo over the first 26 weeks.
  • For research peptides such as BPC-157, there are no large controlled human trials, so no reliable rate exists.

Two injection-site problems are worth knowing by name:

Lipohypertrophy. Repeated injections into the same small area can produce a rubbery lump of thickened fatty tissue. The insulin injection literature links it to poor site rotation and reports that absorption from a lump is blunted and variable. The same recommendations advise against reusing needles, which are no longer sterile after one use. The subcutaneous vs intramuscular guide covers sites.

Infection. A research vial is not made or filled to the standard of a licensed pharmaceutical product, and every puncture of a multi-dose vial is a chance to introduce bacteria. Redness that spreads, warmth, swelling that grows, pus, red streaks or a fever are signs of infection, not a normal reaction. See a doctor.

GH-axis compounds

Compounds that raise growth hormone share a set of effects that follow from higher GH and IGF-1.

  • The tesamorelin label lists fluid retention, which may show up as swelling, joint pain and carpal tunnel symptoms (numbness or tingling in the hand). It also reports worsening glucose control: an HbA1c of 6.5% or more in 5% of treated patients against 1% on placebo. Hypersensitivity reactions occurred in 4%.
  • In a two-year trial of MK-677 in healthy older adults, the most frequent side effects were increased appetite that subsided over a few months, and transient mild leg swelling and muscle pain. Fasting glucose rose by an average of 5 mg/dL and insulin sensitivity fell.

For the shorter-acting peptides such as sermorelin, ipamorelin and CJC-1295, human data is thinner, but the same IGF-1-driven effects are the ones to watch. Glucose and IGF-1 are the labs that matter here.

Healing and other research peptides

For BPC-157, TB-500 and most compounds in this library, published human data is small. The absence of reported side effects in a handful of people is not evidence of safety; it is an absence of data. The practical risks that are well established are the ones that come from the product and the technique: contamination, degradation from heat, and mistakes in reconstitution math. The beginner guide covers the math.

When to see a doctor

Get urgent medical care for any of these:

  • Severe abdominal pain that does not go away, with or without vomiting
  • Vomiting or diarrhoea that stops you keeping fluids down, dizziness on standing, or very little urine
  • Pain in the upper right abdomen, fever, or yellowing of the skin or eyes
  • Swelling of the face, lips or throat, difficulty breathing, or a widespread rash
  • Shakiness, sweating and confusion if you also take insulin or a sulfonylurea
  • Changes in vision if you have diabetes
  • A lump in the neck, hoarseness or trouble swallowing
  • Thoughts of self-harm or a sudden change in mood
  • Signs of injection-site infection: spreading redness, heat, pus or fever

Book a routine appointment for side effects that persist beyond the first weeks after a dose change, for any new symptom you cannot explain, and before any surgery or procedure with sedation. Bring a record of what you took and when; the dose tracker is one way to keep it.