Using lubricant during sex does not create an effective barrier against STD transmission. While lube can help reduce friction and make sexual activity more comfortable, it is not designed to prevent STD transmission and should not be relied upon for protection.

For safer sex practices, I recommend:

1. Using condoms correctly and consistently
2. Getting regular STD testing
3. Having open conversations with sexual partners about STD status

If you're concerned about STD prevention, the most reliable methods are barrier protection methods like condoms, dental dams, and other barrier devices specifically designed for this purpose. Please consult with a healthcare provider for personalized advice about STD prevention strategies that work best for your situation.