Progesterone can potentially cause fatigue or drowsiness as one of its side effects. This is because Progesterone has a calming and sedating effect on the body. During the luteal phase of the menstrual cycle, when Progesterone levels rise, some individuals may experience increased sleepiness or a sense of tiredness. Additionally, Progesterone is known to influence neurotransmitters in the brain, including GABA, which has a relaxing effect. However, it is important to note that the effects of Progesterone can vary between individuals, and not everyone may experience tiredness or fatigue as a result of Progesterone. Other factors such as individual sensitivity, overall health, and lifestyle can also contribute to feelings of tiredness. If you are experiencing significant fatigue or have concerns about the effects of Progesterone, it is recommended to consult with a healthcare professional who can evaluate your specific situation and provide appropriate guidance. They can help determine if Progesterone is the cause of fatigue and offer strategies to manage any related symptoms.