This paper studies the outage performance of transdermal optical wireless communication (OWC) links, in the presence of pointing errors. In this sense, we present a novel tractable path-gain model, which is derived through respective experimental results. Based on this model, we provide the theoretical framework that evaluates and quantifies the impact of pointing errors on transdermal OWC links. In more detail, we obtain a closed-form expression for the outage probability of the optical wireless transdermal link, which takes into account the channel particularities, the transmitter-receiver misalignment, the characteristics of the optical units, as well as, the physical constraints of the in-body device. The results reveal that pointing errors drastically affect the reliability and effectiveness of the link and should be taken into consideration when designing a transdermal OWC link.