Serotonin is the neurotransmitter molecule that induces feelings of happiness, satisfaction, and relaxation. SSRI medications, such as Prozac, work by increasing levels of serotonin. Of my whole molecule jewelry collection, the serotonin necklace is still my favorite. Based on the molecular shape of serotonin, it has a elegant, modern shape and symbolizes the contented feeling of happiness so lacking in our modern, fractured, frenzied lives. It is both a meaningful personal symbol for happiness and a thoughtful gift for someone you wish happiness. The pendant is made of quality, recycled/reclaimed sterling silver, is 1.5 inches wide, and is attached to an 18 inch sterling silver link chain that can be adjusted to shorter lengths. It closes with a lobster clasp. Each is loving made, packaged in a recycled gift box perfect for gift-giving, and includes an informational tag about serotonin. When ordering, please let me know if you'd like a different length than 18 inches. Thank you! ******************************************************* see other serotonin items here: http://www.etsy.com/search_results_shop.php?search_type=user_shop_ttt_id_5165490&search_query=serotonin ******************************************************* Customer comments about this necklace: “Absolutely stunned by how gorgeous this necklace is. It's dainty and beautiful in every way possible, and it's shipping was fast and easy. I'm absolutely 100% satisfied by everything about this.” “Fine craftsmanship, Beautifully done . My Daughter loves this.” “This necklace is just as beautiful as I hoped it would be - it's my favourite thing :0) Thank you!” “A beautiful piece of art, neat and perfectly "nerdy"” “This is absolutely gorgeous!! My sister loves it and wears it all the time. I'd be tempted to get one just like it ^_^ Thank you heaps!!!” “I really love my necklace. :) It arrived beautifully packaged and is such a lovely quality... you can see the quality in the pendant and it feels wonderfully made. Looks lovely on, too! :) I couldn't be happier with it - thanks very much! :D” “My new favorite necklace! It is amazing and I wear it often- thank you!” “love my serotonin necklace! perfect weight - sits perfectly on my neck.” “amazingly beautiful. i love it and never want to take it off!!! and it came fast. thank you so much!” “My most favourite necklace ever! Thank you. It's beautiful and reminds me of happy thoughts.” ...... I'm scientist-turned-artist Raven Hanna of Made With Molecules. I hand-make original, high quality jewelry and use Earth-friendly and people-friendly business practices. I live and work in a solar-powered sugarcane shack on the flank of an active volcano in Hawaii, and I donate a percentage of profits to environmental and science education nonprofit organizations. Please take a look at other molecular jewelry offerings in my shop. http://molecularmuse.etsy.com