<sod>#He is vulnerable to the inert element [[lead]], instead of the radioactive element [[Kryptonite]].<ref>Simultaneous exposure to green Kryptonite and lead negates the latter's harmful effects. In ''Superboy'' #89, having come to suspect that his "brother" may be an impostor, Superboy exposes a sleeping Mon-El to Kryptonite contained in a lead box, and his mystery visitor shows no reaction to either substance. It was stated on at least one occasion pre-Crisis that Kryptonite is one ingredient of Brainiac 5's version of the anti-lead serum.</ref> The Daxamite weakness to lead has been described as an extreme reaction analogous to a near-fatal [[alergy]] in humans.<eod>
<sod>#He is vulnerable to the inert element [[lead]], instead of the radioactive element [[Kryptonite]].<ref>Simultaneous exposure to green Kryptonite and lead negates the latter's harmful effects. In ''Superboy'' #89, having come to suspect that his "brother" may be an impostor, Superboy exposes a sleeping Mon-El to Kryptonite contained in a lead box, and his mystery visitor shows no reaction to either substance. It was stated on at least one occasion pre-Crisis that Kryptonite is one ingredient of Brainiac 5's version of the anti-lead serum.</ref> The Daxamite weakness to lead has been described as an extreme reaction analogous to a near-fatal [[allergy]] in humans.<eod>