{"id":1942,"date":"2026-09-15T15:00:00","date_gmt":"2026-09-15T15:00:00","guid":{"rendered":"https:\/\/lotilabs.com\/resources\/?p=1942"},"modified":"2026-08-01T18:09:47","modified_gmt":"2026-08-01T18:09:47","slug":"ac-262536-emerging-sarm-compound-partial-androgen-receptor-agonist-research-selectivity-profile","status":"publish","type":"post","link":"https:\/\/lotilabs.com\/resources\/ac-262536-emerging-sarm-compound-partial-androgen-receptor-agonist-research-selectivity-profile\/","title":{"rendered":"AC-262536: Emerging SARM Compound, Partial Androgen Receptor Agonist Research &#038; Selectivity Profile"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_83 counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/lotilabs.com\/resources\/ac-262536-emerging-sarm-compound-partial-androgen-receptor-agonist-research-selectivity-profile\/#A_New_Entry_in_the_SARM_Research_Landscape\" >A New Entry in the SARM Research Landscape<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/lotilabs.com\/resources\/ac-262536-emerging-sarm-compound-partial-androgen-receptor-agonist-research-selectivity-profile\/#Androgen_Receptor_Binding_Kinetics\" >Androgen Receptor Binding Kinetics<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/lotilabs.com\/resources\/ac-262536-emerging-sarm-compound-partial-androgen-receptor-agonist-research-selectivity-profile\/#Anabolic-to-Androgenic_Ratio\" >Anabolic-to-Androgenic Ratio<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/lotilabs.com\/resources\/ac-262536-emerging-sarm-compound-partial-androgen-receptor-agonist-research-selectivity-profile\/#Tissue_Selectivity_Mechanisms\" >Tissue Selectivity Mechanisms<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/lotilabs.com\/resources\/ac-262536-emerging-sarm-compound-partial-androgen-receptor-agonist-research-selectivity-profile\/#Comparison_with_Other_SARMs\" >Comparison with Other SARMs<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/lotilabs.com\/resources\/ac-262536-emerging-sarm-compound-partial-androgen-receptor-agonist-research-selectivity-profile\/#Hormonal_Axis_Considerations_in_Research_Models\" >Hormonal Axis Considerations in Research Models<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/lotilabs.com\/resources\/ac-262536-emerging-sarm-compound-partial-androgen-receptor-agonist-research-selectivity-profile\/#Research_Status_and_Availability\" >Research Status and Availability<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"A_New_Entry_in_the_SARM_Research_Landscape\"><\/span>A New Entry in the SARM Research Landscape<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>AC-262536 is a non-steroidal selective androgen receptor modulator (SARM) that has attracted growing attention in research circles for its partial agonist profile at the androgen receptor. First described in a 2007 patent by Acadia Pharmaceuticals (hence the &#8220;AC&#8221; prefix), this compound occupies a distinct pharmacological niche \u2014 it activates the androgen receptor with lower maximal efficacy than testosterone or DHT, producing tissue-selective anabolic effects while maintaining a favorable androgenic-to-anabolic ratio in preclinical models.<\/p>\n<p>Among the growing family of SARMs under investigation, AC-262536 stands out for the simplicity of its pharmacological profile. Where some SARMs are full agonists with tissue selectivity arising from differential coactivator recruitment, AC-262536 achieves selectivity partly through its partial agonist nature \u2014 it cannot drive maximal receptor activation regardless of concentration, placing a ceiling on both desired and undesired effects.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Androgen_Receptor_Binding_Kinetics\"><\/span>Androgen Receptor Binding Kinetics<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>AC-262536 binds to the ligand-binding domain (LBD) of the androgen receptor with moderate affinity. In competitive binding assays, it displaces radiolabeled DHT from AR with a Ki in the nanomolar range, though its absolute affinity is lower than that of steroidal androgens or full-agonist SARMs like LGD-4033 or RAD-140.<\/p>\n<p>The partial agonism is evident in transcriptional reporter assays. In cells transfected with androgen-responsive luciferase reporters, AC-262536 produces approximately 65-70% of the maximal transcriptional activation achieved by DHT at saturating concentrations. This submaximal ceiling is intrinsic to the compound&#8217;s interaction with the receptor \u2014 increasing AC-262536 concentration beyond the point of receptor saturation does not increase transcriptional output beyond this plateau.<\/p>\n<p>Partial agonism has a second pharmacological consequence: in the presence of full agonists, AC-262536 can function as a partial antagonist. By occupying androgen receptors and activating them submaximally, it competes with endogenous androgens for binding and reduces the net androgenic signal when testosterone or DHT concentrations are high. This dual agonist\/antagonist behavior depending on the hormonal environment adds nuance to its pharmacological profile.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Anabolic-to-Androgenic_Ratio\"><\/span>Anabolic-to-Androgenic Ratio<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The defining metric for SARM selectivity is the ratio of anabolic effects (typically measured as levator ani muscle mass in rodent models) to androgenic effects (prostate or seminal vesicle weight). In castrated rat bioassays, AC-262536 demonstrated approximately 66% of the anabolic efficacy of testosterone (muscle accretion) while showing only 27% of testosterone&#8217;s androgenic effect (prostate stimulation).<\/p>\n<p>This yields an anabolic-to-androgenic ratio of approximately 2.45:1 \u2014 meaning the compound&#8217;s muscle effects are roughly 2.5 times greater than its prostate effects relative to testosterone. For context, testosterone itself has a ratio of 1:1 by definition. Other SARMs show varying ratios: LGD-4033 achieves higher absolute anabolic efficacy but with a different selectivity profile; RAD-140 demonstrates a notably high ratio in some assay systems.<\/p>\n<p>The practical implication of AC-262536&#8217;s moderate anabolic efficacy ceiling is that it may produce measurable but bounded muscle effects in research models \u2014 substantial enough for detection but limited by the partial agonism that prevents full receptor activation. This ceiling could be viewed as either a limitation or a feature, depending on the research context.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Tissue_Selectivity_Mechanisms\"><\/span>Tissue Selectivity Mechanisms<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>How does AC-262536 produce different effects in muscle versus prostate? Three mechanisms are proposed, none mutually exclusive.<\/p>\n<p>First, differential coactivator\/corepressor recruitment. The androgen receptor, once ligand-bound, interacts with tissue-specific transcriptional coregulators that determine which genes are activated. Different ligands stabilize different AR conformations, which in turn recruit different coregulator complements. AC-262536&#8217;s binding pose in the LBD may favor coactivators abundant in skeletal muscle while poorly recruiting those enriched in prostate tissue.<\/p>\n<p>Second, differential metabolism. Prostate tissue expresses 5\u03b1-reductase, which converts testosterone to the more potent DHT. Non-steroidal SARMs like AC-262536 are not substrates for 5\u03b1-reductase, so they cannot be locally amplified in prostate tissue the way steroidal androgens are. This enzymatic bypass contributes to reduced androgenic impact in 5\u03b1-reductase-expressing tissues.<\/p>\n<p>Third, partial agonism itself may interact with receptor density. Tissues with high AR expression (prostate) may be more sensitive to the difference between a full and partial agonist than tissues with moderate AR expression (muscle), where the partial agonist may achieve near-maximal functional response through receptor reserve effects.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Comparison_with_Other_SARMs\"><\/span>Comparison with Other SARMs<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Within the SARM research family, AC-262536 occupies a position of moderate potency with relatively clean selectivity. Compared to LGD-4033 (full agonist, high potency, strong anabolic effects but with measurable hormonal suppression), AC-262536 is less potent but potentially less suppressive due to its partial agonist ceiling. Compared to RAD-140 (which shows high anabolic-to-androgenic selectivity with full agonist efficacy in some systems), AC-262536 offers a simpler pharmacological mechanism \u2014 its selectivity does not depend primarily on tissue-specific metabolism but on intrinsic receptor pharmacology.<\/p>\n<p>These comparisons are drawn from preclinical data only. No human studies have been published for AC-262536, and its clinical development status remains preclinical. Researchers evaluating this compound should note that rodent-to-human translation for SARMs has proven inconsistent \u2014 some compounds perform better in humans than preclinical data predicted, others worse.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Hormonal_Axis_Considerations_in_Research_Models\"><\/span>Hormonal Axis Considerations in Research Models<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>All androgen receptor agonists \u2014 including partial agonists \u2014 have the potential to suppress endogenous testosterone production through hypothalamic-pituitary-gonadal (HPG) axis feedback. In preclinical models, AC-262536 produced measurable but modest LH suppression at anabolic concentrations, consistent with its partial agonist nature. Full agonists like testosterone produce near-complete LH suppression at equivalent receptor occupancy, while AC-262536&#8217;s submaximal receptor activation produces proportionally less hypothalamic feedback inhibition.<\/p>\n<p>This characteristic is relevant for researchers designing chronic administration protocols in rodent models, where the degree of HPG axis suppression influences circulating testosterone concentrations and complicates interpretation of AR-mediated endpoints.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Research_Status_and_Availability\"><\/span>Research Status and Availability<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>AC-262536 remains a research compound with no regulatory approvals for any application. Published data is limited primarily to preclinical pharmacology, and its structure-activity relationships have been explored mainly in the context of Acadia Pharmaceuticals&#8217; SARM discovery program. For research laboratories evaluating SARM selectivity mechanisms, AC-262536 offers a useful pharmacological tool: its partial agonism provides a defined ceiling for comparison with full agonist SARMs, and its clean selectivity profile simplifies interpretation of tissue-specific outcomes.<\/p>\n<p><em>Disclaimer: This content is intended for research purposes only and is not meant to constitute medical advice.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>A non-steroidal SARM with partial agonist activity and high anabolic-to-androgenic ratio in preclinical studies \u2014 selectivity and binding kinetics.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"class_list":["post-1942","post","type-post","status-publish","format-standard","hentry","category-peptides"],"_links":{"self":[{"href":"https:\/\/lotilabs.com\/resources\/wp-json\/wp\/v2\/posts\/1942","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lotilabs.com\/resources\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lotilabs.com\/resources\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lotilabs.com\/resources\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lotilabs.com\/resources\/wp-json\/wp\/v2\/comments?post=1942"}],"version-history":[{"count":0,"href":"https:\/\/lotilabs.com\/resources\/wp-json\/wp\/v2\/posts\/1942\/revisions"}],"wp:attachment":[{"href":"https:\/\/lotilabs.com\/resources\/wp-json\/wp\/v2\/media?parent=1942"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lotilabs.com\/resources\/wp-json\/wp\/v2\/categories?post=1942"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lotilabs.com\/resources\/wp-json\/wp\/v2\/tags?post=1942"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}