What is the limit for consuming black seed in excess that would be lethal, as mentioned by Ibn al-Qayyim in his book "Prophetic Medicine"?

The black seed is a cure for every disease except death, as the Prophet, peace and blessings be upon him, informed us, and it has many benefits. However, excessive use of it can be harmful, and moderation is required. Ibn Al-Qayyim mentioned specific quantities for its use in treating some illnesses, but determining the appropriate amount must be done in consultation with a doctor.