Interactive
Pathway map
Pick a receptor or pathway to see every compound in the guide linked to it, or pick a compound to light up the pathways it acts on.
Educational only. A summary of published research, not medical advice or a recommendation. No doses are listed. A simplified map built from each compound's listed targets. Indirect links follow well-established downstream steps, such as growth hormone raising IGF-1.
How to read the map
Pick a pathway or a compound below. Links light up in three styles:
- Acts on it directly
- Studied or proposed link (early research)
- Indirect, through a downstream step
Metabolic hormone receptors
GLP-1 receptor GLP-1R
Receptor for the gut hormone GLP-1, found on insulin-making cells in the pancreas, in the brain and in the gut. Activating it boosts insulin release when blood sugar is high, slows stomach emptying and reduces appetite.
Leads to Insulin receptor & insulin signaling
Acts on it directly (4)
- Semaglutide agonist
- Tirzepatide agonist
- Retatrutide agonist
- Survodutide agonist
Related effects
Metabolic hormone receptors
GIP receptor GIPR
Receptor for GIP, the other main “incretin” gut hormone released after meals. It also boosts insulin release when blood sugar is high, and is found in fat tissue and the brain.
Leads to Insulin receptor & insulin signaling
Acts on it directly (2)
- Tirzepatide agonist
- Retatrutide agonist
Related effects
Metabolic hormone receptors
Glucagon receptor GCGR
Receptor for glucagon, mainly in the liver. Glucagon raises blood sugar, but in weight-loss drugs its receptor is targeted to raise energy use and reduce liver fat, alongside GLP-1 effects.
Acts on it directly (2)
- Retatrutide agonist
- Survodutide agonist
Related effects
Metabolic hormone receptors
Amylin receptors AMY
Receptors for amylin, a hormone released together with insulin. They're formed from the calcitonin receptor plus a partner protein, and signal fullness and slower stomach emptying.
Acts on it directly (1)
- Cagrilintide agonist
Related effects
Metabolic hormone receptors
Calcitonin receptor CTR
Receptor for calcitonin, a thyroid hormone involved in calcium balance. It's also the core of the amylin receptors.
Acts on it directly (1)
- Cagrilintide agonist
Metabolic hormone receptors
Insulin receptor & insulin signaling Insulin
Insulin, released by the pancreas, acts on the insulin receptor to move sugar out of the blood and into cells. Compounds can act upstream (more insulin released when blood sugar is high) or on how sensitive cells are to insulin.
Acts on it directly (1)
- MOTS-c studied link insulin sensitivity in mice
Linked indirectly (4)
- Semaglutide through the GLP-1 receptor
- Tirzepatide through the GIP receptor
- Retatrutide through the GLP-1 receptor
- Survodutide through the GLP-1 receptor
Related effects
Sex-steroid receptors & enzymes
Androgen receptor AR
Receptor for testosterone and DHT. Activating it builds muscle and drives male traits such as body hair and a deeper voice. Every anabolic steroid binds it.
Acts on it directly (12)
- Testosterone agonist
- Nandrolone agonist
- Trenbolone agonist binds very strongly
- Boldenone agonist
- Methandrostenolone agonist
- Oxandrolone agonist
- Oxymetholone agonist
- Stanozolol agonist
- Drostanolone agonist
- Methenolone agonist
- Turinabol agonist
- Methasterone agonist
Related effects
Sex-steroid receptors & enzymes
Progesterone receptor PR
Receptor for the hormone progesterone. Some “19-nor” steroids also act on it, which is linked to some of their side effects.
Acts on it directly (2)
- Nandrolone acts on
- Trenbolone acts on
Sex-steroid receptors & enzymes
Aromatase Aromatase
An enzyme that converts testosterone, and some other steroids, into estrogens such as estradiol. Steroids it works on can cause estrogen-related effects such as water retention and breast tissue growth.
Acts on it directly (3)
- Testosterone converted by converts some to estradiol
- Boldenone converted by reduced conversion to estradiol
- Methandrostenolone converted by converts it to a potent estrogen
Related effects
Sex-steroid receptors & enzymes
5α-reductase 5AR
An enzyme that converts testosterone into DHT, a stronger androgen, in skin, scalp and prostate. It turns nandrolone into a weaker androgen instead.
Acts on it directly (2)
- Testosterone converted by converts some to DHT
- Nandrolone converted by makes a weaker androgen
Related effects
Growth hormone axis
GHRH receptor GHRH-R
Receptor in the pituitary gland for growth hormone–releasing hormone (GHRH). Activating it releases the body's own growth hormone in pulses.
Leads to Growth hormone & GH receptor
Acts on it directly (3)
- Tesamorelin agonist in the pituitary
- Sermorelin agonist in the pituitary
- CJC-1295 agonist in the pituitary
Related effects
Growth hormone axis
Ghrelin receptor GHS-R1a
Receptor for ghrelin, often called the hunger hormone. In the pituitary, activating it also releases growth hormone.
Leads to Growth hormone & GH receptor
Acts on it directly (1)
- Ipamorelin agonist in the pituitary
Related effects
Growth hormone axis
Growth hormone & GH receptor GH
Growth hormone from the pituitary acts on the growth hormone receptor, mainly in the liver, which responds by making IGF-1.
Leads to IGF-1
Linked indirectly (4)
- Tesamorelin through the GHRH receptor
- Sermorelin through the GHRH receptor
- CJC-1295 through the GHRH receptor
- Ipamorelin through the Ghrelin receptor
Related effects
Growth hormone axis
IGF-1 IGF-1
Insulin-like growth factor 1, made mostly in the liver in response to growth hormone. It carries many of growth hormone's effects on growth and tissues.
Linked indirectly (4)
- Tesamorelin through the GHRH receptor
- Sermorelin through the GHRH receptor
- CJC-1295 through the GHRH receptor
- Ipamorelin through the Ghrelin receptor
Related effects
Cell energy & growth signals
AMPK AMPK
An energy sensor inside cells. It switches on when a cell's energy runs low and shifts metabolism toward producing energy.
Acts on it directly (1)
- MOTS-c studied link activated through folate metabolism in cell and mouse studies
Related effects
Cell energy & growth signals
mTOR mTOR
A growth signal inside cells that responds to nutrients and growth factors and drives protein building, including muscle protein synthesis.
No compound in the guide has a documented link to this pathway yet.
Related effects
Cell energy & growth signals
Fat breakdown (lipolysis) Lipolysis
The breakdown of stored fat into fatty acids that the body can burn for fuel.
Acts on it directly (1)
- AOD-9604 studied link designed to mimic growth hormone's fat-breakdown effect
Related effects
Brain signaling
Melanocortin receptors MC1R–MC5R
A family of five receptors. MC1R on pigment cells controls skin color; MC3R and MC4R in the brain affect appetite, energy use and sexual function.
Acts on it directly (2)
- Bremelanotide agonist mainly MC4R in the brain
- Melanotan II agonist nonselective, including MC1R on pigment cells and MC4R in the brain
Related effects
Brain signaling
BDNF BDNF
Brain-derived neurotrophic factor, a protein that supports the growth and connections of nerve cells.
Acts on it directly (1)
- Semax studied link
Related effects
Brain signaling
GABA signaling GABA
GABA is the brain's main calming (inhibitory) chemical signal.
Acts on it directly (1)
- Selank proposed link
Related effects
Brain signaling
Serotonin signaling 5-HT
Serotonin is a chemical signal in the brain involved in mood, anxiety and sleep.
Acts on it directly (1)
- Selank proposed link
Related effects
Brain signaling
Melatonin rhythm Melatonin
Melatonin, made by the pineal gland at night, helps set the body's sleep–wake rhythm.
Acts on it directly (1)
- Epitalon studied link animal studies
Related effects
Repair, blood & aging
Red blood cell production RBC
How the bone marrow makes red blood cells (erythropoiesis). Androgens stimulate it, which is why hematocrit is monitored during testosterone treatment.
Acts on it directly (2)
- Boldenone stimulates
- Oxymetholone stimulates
Repair, blood & aging
Actin Actin
A structural protein inside cells that lets them change shape and move, which matters for wound repair.
Acts on it directly (1)
- TB-500 binds through thymosin beta-4
Related effects
Repair, blood & aging
Blood-vessel growth Angiogenesis
The formation of new blood vessels, part of normal healing.
Acts on it directly (1)
- BPC-157 studied link animal studies
Related effects
Repair, blood & aging
Collagen production Collagen
Collagen is the main structural protein of skin, tendons and connective tissue.
Acts on it directly (1)
- GHK-Cu studied link
Related effects
Repair, blood & aging
Telomerase Telomerase
An enzyme that rebuilds telomeres, the protective caps on chromosomes that shorten each time a cell divides.
Acts on it directly (1)
- Epitalon studied link cell studies
Anabolic steroids
Testosterone
FDA-approved
Binds the androgen receptor to build muscle and drive male traits. Some is converted to estradiol (by aromatase) and to DHT (by 5α-reductase), which explains several side effects. An attached ester (cypionate, enanthate, propionate) slows its release from the injection site.
Anabolic steroids
Nandrolone
Previously approved
Binds the androgen receptor strongly, but is converted to a weaker androgen in skin and scalp than testosterone is. It also acts on progesterone receptors, which is linked to some of its side effects.
Anabolic steroids
Trenbolone
Veterinary only
Binds the androgen receptor very strongly and doesn't convert to estrogen; it also acts on progesterone receptors. In cattle it increases muscle growth and feed efficiency.
Anabolic steroids
Boldenone
Veterinary only
A testosterone derivative with an extra double bond, which reduces its conversion to estradiol. Binds the androgen receptor and stimulates red blood cell production.
Anabolic steroids
Methandrostenolone
Previously approved
A testosterone derivative modified to survive the liver, so it works as a tablet. It converts to a potent estrogen, which drives water retention and breast tissue growth.
Anabolic steroids
Oxandrolone
Previously approved
A DHT-derived steroid that doesn't convert to estrogen, modified to survive the liver so it works as a tablet.
Anabolic steroids
Oxymetholone
FDA-approved
A DHT-derived steroid modified to survive the liver. It stimulates red blood cell production; it doesn't convert to estrogen, yet water retention is commonly reported.
Anabolic steroids
Stanozolol
Previously approved
A DHT-derived steroid that doesn't convert to estrogen. The tablet form is modified to survive the liver.
Anabolic steroids
Drostanolone
Previously approved
A modified form of DHT that binds the androgen receptor and doesn't convert to estrogen.
Anabolic steroids
Methenolone
Not approved
A DHT derivative that doesn't convert to estrogen. Unlike most oral steroids, the tablet form isn't 17α-alkylated.
Anabolic steroids
Turinabol
Not approved
A chlorinated form of methandrostenolone (Dianabol) that doesn't convert to estrogen and is modified to survive the liver.
Anabolic steroids
Methasterone
Not approved
A 17α-methylated form of drostanolone, so it works as a tablet and is hard on the liver.
GLP-1 & weight-loss peptides
Semaglutide
FDA-approved
Mimics the gut hormone GLP-1. A fatty-acid side chain lets it bind to albumin in the blood, which is why a single injection lasts about a week.
Downstream Insulin receptor & insulin signaling
GLP-1 & weight-loss peptides
Tirzepatide
FDA-approved
Activates the receptors for two gut hormones, GIP and GLP-1, which together affect insulin release, appetite and how quickly the stomach empties.
Downstream Insulin receptor & insulin signaling
GLP-1 & weight-loss peptides
Retatrutide
Investigational
Adds glucagon-receptor activity to GIP and GLP-1 effects; glucagon activity is thought to raise energy use and reduce liver fat.
Downstream Insulin receptor & insulin signaling
GLP-1 & weight-loss peptides
Survodutide
Investigational
Pairs GLP-1 effects on appetite with glucagon-receptor activity, which may increase energy use and reduce liver fat.
Downstream Insulin receptor & insulin signaling
GLP-1 & weight-loss peptides
Cagrilintide
Investigational
Activates amylin and calcitonin receptors, slowing stomach emptying and increasing fullness.
Growth hormone secretagogues
Tesamorelin
FDA-approved
Binds GHRH receptors in the pituitary, raising the body's own growth hormone and IGF-1 levels.
Downstream Growth hormone & GH receptor, IGF-1
Growth hormone secretagogues
Sermorelin
Previously approved
Stimulates the pituitary to release growth hormone in natural pulses.
Downstream Growth hormone & GH receptor, IGF-1
Growth hormone secretagogues
CJC-1295
Not approved
Stimulates growth hormone release. The “DAC” version binds albumin in the blood, which greatly extends how long it lasts; versions without DAC (often sold as modified GRF 1-29) are short-acting.
Downstream Growth hormone & GH receptor, IGF-1
Growth hormone secretagogues
Ipamorelin
Not approved
Activates the ghrelin receptor to release growth hormone; in animal studies it had little effect on cortisol or prolactin.
Downstream Growth hormone & GH receptor, IGF-1
Tissue-repair peptides
BPC-157
Not approved
- No established target in people
- Angiogenesis (studied)
Studied in animals for effects on blood-vessel growth, tendon and ligament healing, and repair of the gut lining. How it works in people is not established.
Tissue-repair peptides
TB-500
Not approved
Thymosin beta-4 binds actin, a structural protein inside cells, and has been studied in animals for wound, heart and eye repair.
Tissue-repair peptides
GHK-Cu
Not approved
- Binds copper
- Collagen (studied)
Studied for effects on collagen production, wound healing and skin remodeling. Levels in the body decline with age.
Melanocortin peptides
Bremelanotide
FDA-approved
Activates melanocortin receptors in the brain, mainly MC4R, which are involved in sexual desire.
Melanocortin peptides
Melanotan II
Not approved
Activates several melanocortin receptors, darkening skin pigment and also affecting appetite and sexual function.
Other research peptides
MOTS-c
Not approved
- AMPK (studied)
- Insulin (studied)
- Skeletal muscle (its main target organ in mice)
Studied in mice for effects on insulin sensitivity, metabolism and exercise capacity.
Other research peptides
AOD-9604
Not approved
Designed to mimic growth hormone's fat-breakdown effects without affecting growth or blood sugar.
Other research peptides
Epitalon
Not approved
Studied for effects on telomerase, melatonin rhythm and aging, mostly in cells and animals.
Other research peptides
Selank
Not approved
Studied for anti-anxiety and immune effects; thought to influence GABA and serotonin signaling.
Other research peptides
Semax
Not approved
Studied for effects on brain-derived neurotrophic factor (BDNF) and recovery after stroke.