{"product_id":"mk-2866-s-4","title":"MK-2866 + S-4","description":"\u003ch2 class=\"PDq2pG_selectionAnchorContainer\"\u003eMK-2866 (Ostarine) + S-4 (Andarine) | SARMs Research UK\u003c\/h2\u003e\n\u003ch2 class=\"PDq2pG_selectionAnchorContainer\"\u003eLean Tissue Research Set\u003c\/h2\u003e\n\u003cdiv class=\"qMYqUG_convSearchResultHighlightRoot\"\u003e\n\u003cdiv class=\"\"\u003e\n\u003csection class=\"text-token-text-primary w-full focus:outline-none has-data-writing-block:pointer-events-none [\u0026amp;:has([data-writing-block])\u0026gt;*]:pointer-events-auto R6Vx5W_threadScrollVars scroll-mb-[calc(var(--scroll-root-safe-area-inset-bottom,0px)+var(--thread-response-height))] scroll-mt-[calc(var(--header-height)+min(200px,max(70px,20svh)))]\" dir=\"auto\"\u003e\n\u003cdiv class=\"text-base my-auto mx-auto pb-8 [--thread-content-margin:var(--thread-content-margin-xs,calc(var(--spacing)*4))] @w-sm\/main:[--thread-content-margin:var(--thread-content-margin-sm,calc(var(--spacing)*6))] @w-lg\/main:[--thread-content-margin:var(--thread-content-margin-lg,calc(var(--spacing)*16))] px-(--thread-content-margin)\"\u003e\n\u003cdiv class=\"[--thread-content-max-width:40rem] @w-lg\/main:[--thread-content-max-width:48rem] mx-auto max-w-(--thread-content-max-width) flex-1 group\/turn-messages focus-visible:outline-hidden relative flex w-full min-w-0 flex-col agent-turn\"\u003e\n\u003cdiv class=\"flex max-w-full flex-col gap-4 grow\"\u003e\n\u003cdiv dir=\"auto\" class=\"min-h-8 text-message relative flex w-full flex-col items-end gap-2 text-start break-words whitespace-normal outline-none keyboard-focused:focus-ring [.text-message+\u0026amp;]:mt-1\" tabindex=\"0\"\u003e\n\u003cdiv class=\"flex w-full flex-col gap-1 empty:hidden\"\u003e\n\u003cdiv class=\"markdown prose dark:prose-invert wrap-break-word w-full dark markdown-new-styling\"\u003e\n\u003cp class=\"PDq2pG_selectionAnchorContainer\"\u003eThe BioPlex Lean Tissue Research Set combines MK-2866 (Ostarine) 50×15mg and S-4 (Andarine) 50×15mg, two non-steroidal selective androgen receptor modulators investigated for their interactions with androgen-receptor signalling and tissue-selective research pathways. The set contains one pot of each research compound, creating a paired format for comparative laboratory investigation of two recognised SARMs that share a principal receptor target while maintaining distinct chemical structures, experimental histories and research profiles.\u003cspan class=\"PDq2pG_selectionAnchor\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eMK-2866, commonly known as Ostarine and also associated with the developmental name Enobosarm, is one of the more extensively investigated selective androgen receptor modulators. Research surrounding the compound includes androgen-receptor activity, tissue-selective signalling, lean-tissue-related measurements and other controlled biological endpoints. S-4, commonly known as Andarine, is another genuine selective androgen receptor modulator investigated within androgen-receptor and tissue-response research, although its published evidence profile differs from that of Ostarine.\u003c\/p\u003e\n\u003cp\u003eThese differences make the two compounds particularly relevant for comparative investigation. Rather than treating all compounds classified as SARMs as interchangeable, researchers can examine how structurally different ligands targeting the androgen receptor may demonstrate differing experimental characteristics according to concentration, receptor expression, tissue environment, exposure and selected endpoints.\u003c\/p\u003e\n\u003cp\u003eThe Lean Tissue Research Set name reflects an important area of selective androgen-receptor research rather than promising a particular experimental result. Findings observed with one compound or model should not automatically be transferred to another SARM or research environment.\u003c\/p\u003e\n\u003cp\u003eBy bringing MK-2866 and S-4 together while preserving their individual identities, BioPlex provides a structured research pairing for investigating two recognised androgen-receptor modulators within the same scientific framework. Both compounds are supplied as separately identified 50×15mg capsule products intended strictly for laboratory, analytical and educational research.\u003c\/p\u003e\n\u003ch2\u003e\u003cbr\u003e\u003c\/h2\u003e\n\u003ch2\u003eHow MK-2866 and S-4 Work Together\u003c\/h2\u003e\n\u003cp\u003eMK-2866 (Ostarine) and S-4 (Andarine) share the androgen receptor as their principal molecular research target. The androgen receptor is a ligand-activated nuclear receptor involved in regulating androgen-responsive gene transcription. Interaction between a suitable ligand and this receptor can alter receptor conformation, interactions with regulatory proteins and subsequent transcriptional activity within the biological system being investigated.\u003c\/p\u003e\n\u003cp\u003eThe scientific rationale for placing MK-2866 and S-4 within the same research set therefore comes from examining two chemically distinct compounds operating through a related receptor pathway. Both belong to the selective androgen receptor modulator category, yet this shared classification does not mean their pharmacological or experimental characteristics are identical.\u003c\/p\u003e\n\u003cp\u003eDifferences in molecular structure can affect receptor interaction, exposure, metabolism and downstream responses. Tissue type, receptor density, co-regulatory proteins, concentration and experimental duration may also influence the observations produced by either compound. This makes comparative research particularly important when examining members of the wider SARM category.\u003c\/p\u003e\n\u003cp\u003eMK-2866 has a comparatively developed research history and provides a useful reference compound when considering selective androgen-receptor signalling. S-4 has its own experimental profile and should be interpreted according to evidence specifically associated with Andarine rather than by transferring findings from Ostarine or other SARMs.\u003c\/p\u003e\n\u003cp\u003eWithin controlled research, the pairing can therefore provide a framework for examining receptor activation, transcriptional responses, tissue-selective signalling and compound-specific differences under predefined experimental conditions.\u003c\/p\u003e\n\u003cp\u003eGrouping MK-2866 and S-4 together does not establish that their effects are additive or synergistic. Equivalent nominal quantities also do not establish equivalent receptor occupancy or biological activity. The value of the combination lies instead in comparative investigation of two distinct androgen-receptor ligands, supported by validated compound identity, suitable controls, defined concentrations and clearly established research endpoints.\u003c\/p\u003e\n\u003ch2\u003e\n\u003cbr\u003eMK-2866 (Ostarine) 50×15mg\u003c\/h2\u003e\n\u003cp\u003eMK-2866, commonly known as Ostarine and also associated with the developmental name Enobosarm, is a synthetic non-steroidal selective androgen receptor modulator investigated for its interactions with androgen-receptor signalling. It is one of the most widely recognised compounds within SARM research and has a more developed evidence base than many experimental compounds marketed within the same broad category.\u003c\/p\u003e\n\u003cp\u003eIts principal molecular target is the androgen receptor. This receptor functions as a ligand-activated transcription factor capable of influencing expression of androgen-responsive genes. When MK-2866 interacts with the receptor, the resulting response can depend upon receptor distribution, cellular environment, co-regulatory proteins, compound exposure and the specific endpoint being measured.\u003c\/p\u003e\n\u003cp\u003eOstarine has been investigated across preclinical and clinical research environments involving tissue-related measurements and other biological endpoints. This broader experimental history makes MK-2866 particularly useful when researchers need a comparatively well-characterised androgen-receptor modulator against which other SARM compounds can be considered.\u003c\/p\u003e\n\u003cp\u003eHowever, the existence of a broader research record should not be interpreted as establishing every claim associated with Ostarine. Findings remain dependent upon study design, research population or model, exposure duration and measurement methodology. Observations produced under one experimental condition cannot automatically be generalised to another.\u003c\/p\u003e\n\u003cp\u003eWithin the BioPlex Lean Tissue Research Set, MK-2866 provides the more extensively documented component of the pairing. Its established relationship with androgen-receptor research allows it to be considered alongside the separate experimental profile of S-4 Andarine.\u003c\/p\u003e\n\u003cp\u003eBioPlex also maintains dedicated educational material covering Ostarine MK-2866, including androgen-receptor signalling, SARM selectivity, tissue-marker research and related scientific considerations, providing a wider research-information pathway for researchers examining this compound. \u003cspan class=\"contents\"\u003e\u003cspan class=\"\"\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cbr\u003e\u003c\/h2\u003e\n\u003ch2\u003eS-4 (Andarine) 50×15mg\u003c\/h2\u003e\n\u003cp\u003eS-4, commonly known as Andarine, is a synthetic non-steroidal selective androgen receptor modulator investigated within research concerning androgen-receptor activation and tissue-selective signalling. Its classification as a SARM is based on its relationship with androgen-receptor pharmacology, distinguishing it from compounds sometimes grouped commercially alongside SARMs despite operating through completely different molecular pathways.\u003c\/p\u003e\n\u003cp\u003eThe androgen receptor functions as a ligand-activated nuclear transcription factor. When a suitable compound interacts with the receptor, changes in receptor conformation and co-regulatory interactions can influence expression of androgen-responsive genes. S-4 has been investigated within this wider pharmacological framework as researchers have explored selective androgen-receptor modulation and differences in signalling across experimental tissue models.\u003c\/p\u003e\n\u003cp\u003eS-4 should nevertheless be considered independently from MK-2866. Although both compounds belong to the same broad pharmacological category, their molecular structures, experimental histories and available evidence are not identical. Findings obtained with Ostarine therefore should not automatically be attributed to Andarine.\u003c\/p\u003e\n\u003cp\u003eThis distinction is particularly important when comparing selective androgen receptor modulators. Classification identifies a shared receptor pathway but does not establish equivalent potency, efficacy, pharmacokinetics, tissue selectivity or downstream biological responses. These characteristics require compound-specific investigation under appropriately controlled experimental conditions.\u003c\/p\u003e\n\u003cp\u003eWithin the Lean Tissue Research Set, S-4 provides a second androgen-receptor ligand against which the more extensively researched MK-2866 can be considered. This creates a structured framework for investigating similarities and differences between two recognised selective androgen receptor modulators while maintaining clear separation between their individual evidence profiles.\u003c\/p\u003e\n\u003cp\u003eBioPlex's wider SARMs research material also distinguishes compounds such as Ostarine and Andarine from other research chemicals according to their molecular classification and androgen-receptor pathway, helping support accurate interpretation of the SARMs research category. \u003cspan class=\"contents\"\u003e\u003cspan class=\"\"\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\n\u003cbr\u003eExplore Related Research Compounds\u003c\/h3\u003e\n\u003cp\u003eContinue exploring related androgen-receptor and SARMs-category research compounds from BioPlex.\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/bioplexpeptides.co.uk\/products\/mk-2688-ostarine-br-50x15mg\" title=\"MK-2866 Ostarine | Research SARM Capsules | BioPlex UK\"\u003eView MK-2866 Ostarine 50×15mg Research Capsules ⟶\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/bioplexpeptides.co.uk\/collections\/sarms\" title=\"S-4 Andarine | Research SARM Capsules | BioPlex UK\"\u003eView S-4 Andarine 50×15mg Research Capsules ⟶\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003e\u003ca title=\"SARMs Research Compounds UK | BioPlex Peptides\" rel=\"noopener\" class=\"decorated-link\" href=\"https:\/\/bioplexpeptides.co.uk\/collections\/sarms?utm_source=chatgpt.com\"\u003eExplore All BioPlex SARMs Research Compounds ⟶\u003c\/a\u003e\u003c\/p\u003e\n\u003ch3\u003e\n\u003cbr\u003eExplore BioPlex Research Information\u003c\/h3\u003e\n\u003cp\u003eAccess BioPlex SARMs guidance, company information and the complete research product range.\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/bioplexpeptides.co.uk\/collections\/sarms\" title=\"SARMs Research Compounds UK | BioPlex Peptides\"\u003eExplore the BioPlex SARMs Research Range ⟶\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/bioplexpeptides.co.uk\/pages\/about-bioplex\" title=\"About BioPlex Peptides UK | Research Compound Supplier\"\u003eLearn More About BioPlex Peptides ⟶\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/bioplexpeptides.co.uk\/collections\/all\" title=\"BioPlex Peptides | All Research Products\"\u003eView All BioPlex Research Products ⟶\u003c\/a\u003e\u003c\/p\u003e\n\u003ch3\u003e\n\u003cbr\u003eExplore Related Research Articles\u003c\/h3\u003e\n\u003cp\u003eContinue your research with BioPlex articles covering Ostarine MK-2866, selective androgen-receptor signalling and the wider SARMs research category. BioPlex's live research library includes a dedicated Ostarine MK-2866 Research Overview. \u003cspan class=\"contents\"\u003e\u003cspan class=\"\"\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/bioplexpeptides.co.uk\/blogs\/sarms-research-articles-bioplex-peptides-uk\" title=\"Ostarine MK-2866 Research Overview | BioPlex Peptides\"\u003eRead the Ostarine MK-2866 Research Overview ⟶\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/bioplexpeptides.co.uk\/blogs\/sarms-research-articles-bioplex-peptides-uk\" title=\"SARMs Research Articles | BioPlex Peptides UK\"\u003eExplore All BioPlex SARMs Research Articles ⟶\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003e\n\u003cbr\u003eDisclaimer\u003c\/h2\u003e\n\u003cp\u003e\u003ca class=\"decorated-link\" rel=\"noopener\" title=\"Legal Notice | BioPlex Peptides UK\" href=\"https:\/\/bioplexpeptides.co.uk\/policies\/legal-notice\"\u003eFor research purposes only. Not for human consumption\u003c\/a\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/section\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"BioPlex Peptides","offers":[{"title":"Default Title","offer_id":58753125515648,"sku":null,"price":86.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0991\/6783\/0400\/files\/MK-2866_S-4.png?v=1787431877","url":"https:\/\/bioplexpeptides.co.uk\/lv\/products\/mk-2866-s-4","provider":"BioPlexPeptides.co.uk","version":"1.0","type":"link"}