Merits of Zamzam Water
Question

Does Zamzam water have any significance? Is there any hadith to say it is used for cures, etc. and or keep niyyah and drink it for a purpose?
Praise be to Allah.What is Zamzam?
Zamzam is the name of a famous well in al-Masjid al-Haram [the Sacred Mosque in Makkah], which is thirty-eight cubits away from the Ka`bah. It is the well of Isma’il, the son of Ibrahim (peace and blessings of Allah be upon them both), from which Allah quenched the thirst of Isma’il when he was an infant. His mother looked for water for him, but could not find any. She climbed to the top of al-Safa, praying to Allah to help her and give her water for Isma’il, then she climbed to the top of al-Marwah and did the same. Allah sent Jibril, and he struck the earth with his heels, and water appeared.
Virtues of drinking from the water of Zamzam
The scholars (may Allah have mercy on them) agreed that it is recommended for pilgrims on Hajj and `Umrah in particular, and for all Muslims in general, to drink Zamzam water, because of the authentic hadith in which the Prophet (peace and blessings of Allah be upon him) is reported to have drunk the water of Zamzam . (Al-Bukhari, 3/492) 
According to the hadith of Abu Dharr (may Allah be pleased with him), the Prophet (peace and blessings of Allah be upon him) said concerning the water of Zamzam, “It is a blessing, and it is food that satisfies.” (Reported by Muslim, 4/1922). Al-Tayaalisi (61) added, in a version that he narrated: “and a cure for the sick.” I.e., drinking the water of Zamzam means that a person does not need to eat, and it will cure his sickness – but this is when he drinks it with faith and sincerity, as proven in the hadith of Abu Dharr al-Ghifari who stayed in Makkah for a month without any nourishment except Zamzam water.
Al-`Abbas ibn ‘Abd al-Muttalib (may Allah be pleased with him) said: “The people used to compete over Zamzam during the time of Jahiliyyah. People who had children used to bring them and give them to drink, and this was their early-morning victuals. We used to used to think that it was a help for people who had children.” Al-'Abbas said: “During the Jahiliyyah, Zamzam was known as Shaba’ah (satisfaction).”
Al-‘Allamah al-Abbi (may Allah have mercy on him) said:
“(The water) is for whatever purpose it is drunk for, and Allah made it food and drink for Isma’il and his mother Hajar .”
Ibn al-Mubarak entered Zamzam and said, “O Allah, Ibn al-Mu’ammal told me, from Abu’l-Zubayr from Jabir that the Messenger of Allah (peace and blessings of Allah be upon him) said: ‘The water of Zamzam is for whatever purpose it is drunk for,’ so, O Allah, I am drinking it (to quench) my thirst on the Day of Resurrection.”
The two angels washed the heart of the Prophet (peace and blessings of Allah be upon him) when he was a child, after they had taken it out, then they put it back. Al-Hafiz al-'Iraqi (may Allah have mercy on him) said: “The reason why the Prophet’s chest was washed with Zamzam water was to make him stronger so that he could see the kingdom of heaven and earth, and Paradise and Hell, because one of the special qualities of Zamzam is that it strengthens the heart and calms the soul. The report about the chest of the Prophet (peace and blessings of Allah be upon him) being washed with the water of Zamzam is proven in the hadith of Abu Dharr (may Allah be pleased with him), who reported that the Prophet (peace and blessings of Allah be upon him) said: “My roof was opened when I was in Makkah, and Jibril (peace be upon him) came down and opened my chest, then he washed it with Zamzam water. Then he brought a gold basin full of wisdom and faith, poured it into my chest, and closed it up again. Then he took me by the hand and ascended with me into the first heaven.” (Reported by al-Bukhari, 3/429)
How to drink Zamzam water
It is sunnah to drink one’s fill of Zamzam water and to quench one’s thirst.
The jurists have mentioned the etiquette that is recommended when drinking Zamzam water, such as facing the Ka`bah , saying Bismillah, pausing to take a breath three times, drinking one’s fill, praising Allah after one finishes, and sitting whilst drinking it, as one should do when drinking other kinds of drinks. 
As regards the hadith of Ibn `Abbas (may Allah be pleased with him), who said, “I gave the Prophet (peace and blessings of Allah be upon him) Zamzam water to drink whilst he was standing,” (reported by al-Bukhari, 3/492), it is taken to mean that it is permissible to drink whilst standing, and the disapproval of doing so is understood to mean that it is disliked. 
The scholars also recommended that the person who drinks Zamzam water should sprinkle some of it on his head, face and chest, make lots of du`a when drinking it, and to drink it for a purpose that will benefit him in this world or the next, because of the hadith in which the Prophet (peace and blessings of Allah be upon him) said: “The water of Zamzam is for whatever purpose it is drunk for.” (Reported by Ibn Majah, 2/1018; see Al-Maqasid al-Hasanah by al-Sakhawi, p. 359)
When Ibn `Abbas (may Allah be pleased with him) drank from the water of Zamzam, he said: “O Allah, I ask you for beneficial knowledge, plentiful provision and healing from every disease.”
Al-Daynuri reported that al-Humaydi said: “We were with Sufyan ibn ‘Uyaynah, and he told us the hadith about the water of Zamzam being drunk for whatever purpose it is drunk for. A man got up and left the gathering, then he came back and said, ‘O Abu Muhammad, is the hadith which you told us about the water of Zamzam sahih?’ He said, ‘Yes.’ The man said, ‘Just now I drank a bucket of Zamzam so that you would tell me one hundred hadiths.’ Sufyan said, ‘Sit down,’ so he sat down and he told him one hundred hadiths.”
Can you take Zamzam water back to your country?
Some jurists recommended that people should take some Zamzam water back with them to their countries, because it is a cure for those who seek healing. `Aishah reported that she took Zamzam water home with her in bottles, and said, “The Messenger of Allah (peace and blessings of Allah be upon him) took some of it away with him, and he used to pour it on the sick and give it to them to drink.” (Reported by al-Tirmidhi, 4/37)
The jurists agreed that it is permissible to use Zamzam water to purify oneself , but they advised that it should not be used for any inappropriate purposes such as removing impurity and so on. 
Al-‘Allamah al-Bahuti (may Allah have mercy on him) said in his book Kashshaf al-Qina’: 
“Only this (using Zamzam water to remove najasah) is considered to be makruh, out of respect, but it is not makruh to use it to purify oneself, because ‘Ali said: ‘The Messenger of Allah (peace and blessings of Allah be upon him) departed (from Muzdalifah) and called for a bucket of Zamzam water. He drank from it, then did wudu. (Reported by ‘Abd-Allah ibn Ahmad with a sahih isnad).” (See Nayl al-Awtar, Kitab al-Taharah, Bab Tahuriyyat al-Bahr).
Al-Hafiz al-Sakhawi (may Allah have mercy on him) said in Al-Maqasid al-Hasanah:
“Some people said that the virtue (of Zamzam water) remains only so long as it is in its place (of origin), and that when it is taken away, it changes. This is an idea that has no basis. The Prophet (peace and blessings of Allah be upon him) wrote to Suhayl ibn `Amr: “If my letter reaches you at night, do not wait until morning, and if it reaches you during the day, do not wait until evening, to send me some Zamzam water.” He sent him two containers full, and at that time he was in Madinah, before the Conquest of Makkah. This hadith is hasan because of corroborating evidence. `Aishah also used to take Zamzam water away with her, and she reported that the Prophet (peace and blessings of Allah be upon him) used to do this; he used to carry it in small vessels and buckets, and pour it onto the sick and give it to them to drink. 
Whenever a guest visited Ibn `Abbas he would honour him by giving him Zamzam to drink. `Ata was asked about taking Zamzam water away, and he said: “The Prophet (peace and blessings of Allah be upon him), al-Hasan and al-Husayn all took it away with them.”
And Allah knows best.