Why Side Effects Occur
Peptide therapies, like all pharmacologically active compounds, interact with biological systems in ways that can produce both intended therapeutic effects and unintended side effects. Understanding why side effects occur is essential for informed decision-making. Most peptide side effects are mechanism-based — they arise directly from the same pharmacological action that produces the therapeutic benefit, rather than from off-target toxicity.
For GLP-1 receptor agonists such as semaglutide and tirzepatide, the most common side effects are gastrointestinal: nausea, vomiting, diarrhoea, and constipation. These occur because GLP-1 receptors in the gut mediate gastric emptying — slowing digestion is both the mechanism by which these drugs promote satiety and the cause of GI discomfort. Fortunately, these effects are typically transient, peaking during the initial weeks of treatment and dose escalation, then diminishing as the body adapts.
Common Side Effects by Peptide Class
Regenerative peptides such as BPC-157 and TB-500 generally have a favourable tolerability profile, with injection site reactions (mild redness, swelling, or itching) being the most frequently reported adverse event. Systemic side effects are uncommon in the published literature, though it must be noted that large-scale Phase III trials are still limited for many regenerative peptides. Headache and transient dizziness have been reported in a small percentage of patients.
NAD+ infusions present a unique side-effect profile. During IV administration, patients may experience flushing, chest tightness, nausea, or a sensation of warmth — these are rate-dependent effects that resolve by slowing the infusion speed. Post-treatment fatigue or mild headache can occur as cellular repair processes are upregulated. These effects are generally well-tolerated and self-limiting within 24–48 hours.
Risk Mitigation at DOSIST
The key to minimising side effects is proper medical supervision, structured dose titration, and individualised treatment planning. At DOSIST, every patient undergoes a comprehensive pre-treatment assessment including relevant blood work, medical history review, and contraindication screening. Dose escalation follows evidence-based protocols, and patients have direct access to their prescribing clinician for ongoing support and adjustment.
- GLP-1 RA GI side effects are mechanism-based and typically transient
- Regenerative peptide side effects are generally limited to injection site reactions
- NAD+ infusion effects are rate-dependent and managed by adjusting infusion speed
- Structured dose titration and medical oversight are the most effective risk mitigation strategies
