Contact QSC
Get in touch with our team for orders, inquiries, and support
QSC Sales Team
Alisa Yang
Sales ManagerAlisa oversees all business operations including custom synthesis, OEM partnerships, bulk pricing, and wholesale enquiries.
Tracy
Fastest ResponseSales Representative
Tracy handles all orders, product questions, shipping updates, and after-sale support by email.
Security Notice: Tracy and Alisa are our only official sales representatives, and Gemma Conway is our only official support agent on Telegram and WhatsApp. Email remains our main contact channel — always check you are corresponding with alisayang@qingdaosigma.com or messaging Gemma via the official links on this page.
Gemma Conway
Support AgentQuestions about the shop, your order, or our products — message Gemma on Telegram or WhatsApp. Email remains our main contact.
Other Ways to Reach Us
Buyer Protection
100% Delivery Guarantee
Package seized or lost? We reship at no cost — no questions asked.
60-Day Refund Policy
Full refund, free replacement, or 110% store credit within 60 days.
Secure Payments
256-bit encrypted. Visa, MC, Apple Pay, Google Pay, Bank Transfer, Crypto.
Discreet Packaging
Plain, unmarked — no labels or branding visible.
Shipping Information
Qingdao, China
7-15 business days worldwide
$25 worldwide with tracking
$50 — fully tracked via USPS, Royal Mail, DHL, etc.
Our Services
OEM Service
Custom manufacturing for bulk orders
Janoshik Testing
Third-party analytical verification
Bulk Discounts
Volume pricing for institutions
Custom Synthesis
Bespoke compound formulation