The critical safety concern is not reduced fertility but rather the potential for pregnancy during treatment
2019 May 31;24(11):2076
Research in cell culture and rodent models consistently demonstrates that MOTS-c accelerates this translocation independently of insulin, offering a distinct and additive mechanism to insulin sensitizers like Metformin [1]
There is strong evidence that exposure to a number of animal allergens can lead to primary sensitization and an increased risk of developing allergic disease (Colloff et al., 1992)

Contact your healthcare provider promptly if you experience: Severe or persistent heartburn unresponsive to over-the-counter antacids or lifestyle modifications Difficulty swallowing (dysphagia) or painful swallowing (odynophagia), which may indicate esophageal inflammation or stricture Persistent nausea and vomiting that prevents adequate oral intake or leads to dehydration Vomiting blood (hematemesis) or material resembling coffee grounds Black, tarry stools (melena) or visible blood in stool Severe abdominal pain, particularly if localized to the upper abdomen or radiating to the back (stop medication immediately if pancreatitis is suspected) Right upper quadrant pain, fever, or yellowing of skin/eyes, which may indicate gallbladder disease Unintentional weight loss beyond expected therapeutic effects New or worsening chest pain (call 911 if concerning for heart attack), especially if accompanied by shortness of breath These symptoms may indicate complications such as erosive esophagitis, gastrointestinal bleeding, pancreatitis, or gastroparesis

However, its important to manage expectations, as it hasnt shown vastly different results compared to a placebo