Tadalafil side effects on day 8: what's normal and what's not

What's this video probably claiming?

Based on the caption, @roadto80kgs is documenting a rough first week-plus on tadalafil, describing symptoms that sound more like a systemic illness than the standard "mild headache" disclaimer you see in drug information leaflets. The creator is likely framing this as a cautionary personal account, questioning whether flu-like muscle aches, nausea, vomiting, and hot-and-cold sweats are a normal part of starting tadalafil, especially in the context of a broader TRT protocol (the hashtags reference testosterone and hypogonadism). The implicit claim is that tadalafil side effects can be significantly more severe than the medical community typically communicates, and the creator seems to be reaching out to a community of users for validation or reassurance. That framing deserves scrutiny, because some of what he describes is documented, some is unusual, and some may point to something else entirely.

What does the science actually show?

Tadalafil, a PDE5 inhibitor, does carry a real side effect profile. The most commonly reported adverse events in clinical trials are headache (occurring in roughly 11-15% of patients at the 5mg daily dose), myalgia or back pain (around 5-6%), flushing, dyspepsia, and nasal congestion (Porst et al., 2006, European Urology). These are usually mild to moderate and tend to resolve within two weeks of continued use. Nausea is less commonly reported in isolation and severe systemic symptoms like sweating episodes and vomiting are not the expected clinical picture. A 2016 Cochrane review of daily tadalafil for erectile dysfunction confirmed that most adverse events peak early and diminish, but discontinuation rates due to adverse events still ran at around 4-6%. Myalgia specifically, described as diffuse muscle aches, is attributed to PDE5 inhibition in smooth muscle tissue and is considered a class effect, not unique to tadalafil.

Where does the social media noise diverge from clinical reality?

Here is where it gets worth paying attention to. The TRT hashtag context matters. If this creator is taking tadalafil alongside testosterone (a common combination in performance and hormone optimization circles), the symptom picture changes. TRT itself, particularly in the early weeks of dose adjustment, can cause systemic symptoms: night sweats, nausea, fatigue, and myalgia are all documented during the estradiol fluctuation period that follows testosterone initiation or dose changes (Baillargeon et al., 2014, Journal of Clinical Endocrinology and Metabolism). Social media communities tend to attribute every symptom to whatever was started most recently, which creates a real attribution problem. The creator started tadalafil on day 8, but if testosterone was introduced around the same time, the "tadalafil is wrecking me" narrative may be misleading. Additionally, flu-like symptoms with sweating and vomiting at day 8 on any new medication warrant a clinical evaluation, not crowdsourced reassurance from TikTok comments.

What should you actually know?

Tadalafil is a well-studied drug with a generally manageable side effect profile when used at clinically appropriate doses under medical supervision. Myalgia and back pain are real and documented, particularly in the first one to two weeks. However, the symptom cluster this creator describes, specifically vomiting, hot and cold sweats, and being "wiped out," is not a standard tadalafil presentation and should not be normalized by online communities or framed as something to push through. A prescribing clinician needs to know this is happening. There are also real drug interaction considerations: tadalafil is contraindicated with nitrates and can interact with alpha-blockers in ways that cause hypotension, which could explain systemic symptoms if the creator is taking other compounds. The decision to continue without medical review is the part of this video that deserves the most pushback, not the side effect experience itself.