Related by context. Frequent words. (Click for all words.) 64 endorphins 62 releases endorphins 62 Cortisol 62 hormone cortisol 60 stress hormones 59 chemical serotonin 59 noradrenaline 58 endorphin 57 neurotransmitter serotonin 57 Ghrelin 56 stress hormone cortisol 56 hormone melatonin 56 chemical messengers 56 neurotransmitters 56 neurotransmitter dopamine 55 cortisol 55 serotonin 55 hormone oxytocin 54 norepinephrine 53 chemical dopamine 53 Oxytocin 53 dopamine 53 naturally occurring hormone 53 Serotonin 53 endocannabinoids 53 hormones 53 corticosterone 52 prolactin 52 histamines 52 orexin 52 reproductive hormones 52 nitric oxide 52 hormone 51 cannabinoid receptors 51 dopamine receptors 51 female hormone estrogen 51 sebaceous glands 51 vasopressin 51 GABA 51 acetylcholine 50 estrogen hormone 50 relaxant 50 hormone testosterone 50 muscle contractions 50 neurotransmitter 50 metabolically active 50 brain derived neurotrophic 50 adenosine 50 melatonin 50 vasodilator 50 Dopamine 50 prostaglandins 50 glucocorticoid 49 glucose uptake 49 vasodilation 49 adrenal glands 49 testosterone 49 neurochemical 49 aldosterone 49 hormones estrogen 49 hormone leptin 49 nitric oxide NO 49 Aerobic exercise 49 citrulline 48 steroid hormones 48 pineal gland 48 Nitric oxide 48 excitatory 48 oxytocin 48 retinoic acid 48 male hormone testosterone 48 NPY 48 calcitriol 48 dopamine neurons 48 thyroid hormone 48 estrogen 48 glutamate 48 Nitric Oxide 48 interferon gamma 48 sexual arousal 48 PGE2 48 oxygen uptake 48 physiologically 47 metabolism 47 vasoconstriction 47 serotonin receptors 47 inflammatory cytokines 47 Melatonin 47 Hormones 47 hormone estrogen 47 cortisol levels 47 sebum 47 gastric acid 47 uric acid levels 47 sensory nerves 47 skeletal muscles 47 leptin 47 B Vitamins 47 hormonal 47 RANKL 47 pharmacologically