Solubility and Texture Issues with N-Acetyl Cysteine and Slim-Coffee (Caffeine) in Essence

Based on the conversation with the staff, the issue likely occurred because you mixed the N-Acetyl Cysteine and Slim-Coffee (Caffeine) together before dissolving them separately in water. These ingredients need to be dissolved individually for proper incorporation into the essence.

Here is the recommended method based on the staff's successful test:

1. Measure all ingredients by weight (grams), as you corrected.
2. Add the N-Acetyl Cysteine to the distilled water and stir until it is completely dissolved and the solution is clear.
3. Add the Slim-Coffee (Caffeine) to the same water mixture and stir until it is completely dissolved and the solution is clear.
4. Once both are fully dissolved, add the other ingredients (Biotin Express, Copper Peptide, Preservative) and mix well.

The staff also suggested that the amount of N-Acetyl Cysteine and Slim-Coffee (Caffeine) you used (5g each) might be too high for the amount of water, potentially contributing to the difficulty in dissolving and the cream-like consistency. They recommend trying with a reduced amount, such as 3g of N-Acetyl Cysteine and 3g of Slim-Coffee (Caffeine).

Regarding the smell, N-Acetyl Cysteine is known to have a strong, sulfurous odor, which might be what you are smelling. Proper dissolution might help, but some smell from this ingredient is expected, especially at higher concentrations.