There are a few medicines and herbs that can effectively cancel your appetite for the entire day. I have taken one and I don't feel hungry or thirsty for the whole period of the fast. I asked my imam if this was ok, and he said there is nothing in the Islamic texts that mention any prohibitions or restrictions for this.
To me, it seems like cheating. I'm sure I'm not the first to question this.
There is no evidence to show whether or not it is makruh or haram but it is permissible as it would contain vitamins that are essential for the brain.
There is no difference in these tablets and food eaten in suhur in regards to making fasting more bearable and easier meaning there is no need to take these.
عَنْ أَنَسٍ، - رضى الله عنه - قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " تَسَحَّرُوا فَإِنَّ فِي السُّحُورِ بَرَكَةً "
It was narrated that Anas ibn Maalik (may Allah be pleased with him) said: The Prophet (blessings and peace of Allah be upon him) said: “Eat sahoor, for in sahoor there is blessing.”
Narrated by al-Bukhaari (1823) and Muslim (1095).
Al-Haafiz Ibn Hajar said:
In the hadeeth of Anas, “Eat sahoor, for in sahoor there is blessing”, what is meant by blessing is reward, or it is blessed because it gives one strength and energy to fast, and makes it less difficult.
[Fath al-Baari, 4/140]
Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allah have mercy on him) said, discussing the blessings of sahoor:
One of its blessings is that it supplies nourishment to the body throughout the day and helps one to be patient in refraining from food and drink, even during the long, hot days of summer, whereas when a person is not fasting you will find him drinking five or six times a day, and eating twice. But Allah has instilled blessing in sahoor, so it makes the body able to cope with fasting.
[Liqa’ al-Baab al-Maftooh (Introduction to no. 223)]
To summarise up, it is preferable to eat during Suhur as you will gain more blessings but there is no problem in having the tablet.
And Allah knows best.
