Citrulline

Citrulline (usually L-citrulline, sometimes “citrulline malate”) is an amino acid supplement commonly used for blood-flow support and exercise performance. In the body, citrulline is converted into arginine, which is used to produce nitric oxide (NO)—a signaling molecule that helps relax smooth muscle and improve circulation. Because erections rely heavily on NO-mediated blood flow in penile tissue, citrulline often comes up as a relatively “light-touch” option people try for erectile support.

In PFS/PSSD/PAS discussions, citrulline is mostly framed as a symptom-support tool rather than something expected to “treat the root.” Still, there are recurring anecdotes of better erection quality and sometimes a noticeable increase in libido/arousal responsiveness, especially for people who feel their biggest limitation is blood flow or responsiveness rather than desire alone. Just as commonly, others report minimal change—so it tends to be described as a “maybe helpful, maybe neutral” experiment rather than a consistent lever.

On the risk side, citrulline is often viewed as lower-risk than hormone-active or strongly serotonergic substances, but it’s not guaranteed neutral for everyone. Some people report vasodilation-type side effects (headache, flushing, reflux, lightheadedness) or feeling slightly “off,” particularly at higher doses or when combined with other vasodilators (like PDE5 inhibitors or alcohol). Severe or lasting worsening doesn’t seem to be a dominant theme in community talk, but individual sensitivity varies—so the most cautious framing is: if someone tries it, keep variables simple, watch for a consistent pattern, and discontinue if it clearly worsens symptoms.

Anecdotes (Community Reports):

https://www.reddit.com/r/PSSD/comments/16at1sk/lcitrulline_holy_f/

https://www.reddit.com/r/PSSD/comments/1hdt903/lcitrulline_malate_works_amazing_no_viagra_or/

https://www.reddit.com/r/PSSD/comments/w3anl1/lcitrulline_trial_why_this_remedy_is_overlooked/