From a biophysical perspective, the interactions between hydrophobic molecules and cell membranes are integral to a variety of open questions, such as lipid droplet formation , the effect of micro-and nanoplastic pollution on living cells or nanoparticle design for drug delivery . Various drugs show crystal polymorphism and the crystal properties are often related to stability and performance . Moreover, such drugs can potentially crystallize inside their carrier nanoparticles or in a biological environment . It is therefore essential to understand the crystallization behaviour in detail, such that one may control it. However, we still lack understanding of allegedly simple scenarios. For example, to our knowledge, the potential crystallization of purely hydrophobic, chain-like molecules inside a lipid membrane has never been reported.