  The presence of a dissipative dark matter (DM) sector may allow for the
trapping of a significant DM mass inside stars, either during structure
formation or by accretion over their lifetime, influencing stellar behavior
well into the Main Sequence stage. Motivated by this scenario, we place an
upper bound on the fractional DM mass within current-day Main Sequence stars.
Using double-lined spectroscopic binaries (SB2 stars), gravitational masses are
extracted and contrasted with luminous masses, derived using a modified
mass-luminosity relation which accounts for the effect of DM. High-accuracy
mass and luminosity data from a sample of 486 binary stars in the $0.18 <
M/M_\odot < 31$ mass range are partitioned into appropriate mass domains and
analyzed. A 95% C.L. upper limit of sub-5% is found for the subset of 263 stars
in the $1 < M/M_\odot < 2.4$ regime.
